Catalyst system for polymerization of an olefin

ABSTRACT

A catalyst system including a procatalyst, a co-catalyst and an external electron donor of Formula I′: 
       Si(L) n (OR 11 ) 4-n-m (R 12 ) m   Formula I′
     wherein,   Si has a valency 4+;   O has a valency 2− and O is bonded to Si via a silicon-oxygen bond;   n is 1-4;   m is 0-3;   n+m≦4;   each R 11  and R 12  group is independently an alkyl or aromatic substituted or unsubstituted hydrocarbyl;
 
each L group is independently of Formula II:
   

     
       
         
         
             
             
         
       
         
         wherein, 
         L is bonded to the silicon atom via the nitrogen-silicon bond; 
         L has a single substituent on the nitrogen atom, where this single substituent is an imine carbon atom; and 
         X and Y are independently a hydrogen atom; a heteroatom of Groups 13-17; an alkyl, optionally containing a heteroatom of Groups 13-17 or an aromatic substituted and unsubstituted hydrocarbyl, optionally containing a heteroatom of Groups 13-17.

The present invention relates to a catalyst system comprising aZiegler-Natta type procatalyst, a co-catalyst and an external electrondonor comprising a silicon compound. The invention also relates to aprocess for obtaining a polyolefin by applying said catalyst system andto a polyolefin obtainable by said process. The invention also relatesto the use of said silicon compound as an external electron donor forpolymerization of an olefin.

BACKGROUND

Catalyst systems and their components that are suitable for preparing apolyolefin are generally known. One type of such catalysts are generallyreferred to as Ziegler-Natta catalysts. The term “Ziegler-Natta” isknown in the art and it typically refers to catalyst systems comprisinga transition metal-containing solid catalyst compound (also typicallyreferred to as a procatalyst); an organometallic compound (alsotypically referred to as a co-catalyst) and optionally one or moreelectron donor compounds (e.g. external electron donors).

The transition metal-containing solid catalyst compound comprises atransition metal halide (e.g. titanium halide, chromium halide, hafniumhalide, zirconium halide or vanadium halide) supported on a metal ormetalloid compound (e.g. a magnesium compound or a silica compound). Anoverview of such catalyst types is for example given by T. Pullukat andR. Hoff in Catal. Rev.—Sci. Eng. 41, vol. 3 and 4, 389-438, 1999. Thepreparation of such a procatalyst is for example disclosed in WO96/32427A1.

One of the functions of an external donor compound is to affect thestereoselectivity of the catalyst system in polymerization of olefinshaving three or more carbon atoms. Therefore it may be also referred toas a selectivity control agent.

The use of silicon compounds as external donors is known in the priorart as being used as external electron donors in Ziegler-Natta catalystsystems for polymerization of olefins. The art presently recognizes afinite set of compounds suitable for use as external donors.

Documents EP1538167 and EP1783145 disclose a Ziegler-Natta catalyst typecomprising an organo-silicon compound as external donor that isrepresented by formula Si(OR^(c))₃(NR^(d)R^(e)), wherein R^(c) is ahydrocarbon group having 1 to 6 carbon atoms, R^(d) is a hydrocarbongroup having 1 to 12 carbon atoms or hydrogen atom, and R^(e) is ahydrocarbon group having 1 to 12 carbon atoms used as an externalelectron donor.

Typical external donors known in the art (for instance as disclosed indocuments WO2006/056338A1, EP1838741B1, U.S. Pat. No. 6,395,670B1,EP398698A1, WO96/32426A) are organosilicon compounds having generalformula Si(OR^(a))_(4-n)R^(b) _(n), wherein n can be from 0 up to 2, andeach R^(a) and R^(b), independently, represents an alkyl or aryl group,optionally containing one or more hetero atoms for instance O, N, S orP, with, for instance, 1-20 carbon atoms; such as n-propyltrimethoxysilane (nPTMS), diisobutyl dimethoxysilane (DiBDMS), t-butylisopropyl dimethyxysilane (tBiPDMS), cyclohexyl methyldimethoxysilane(CHMDMS), dicyclopentyl dimethoxysilane (DCPDMS), di(iso-propyl)dimethoxysilane (DiPDMS).

EP 1 197 497 relates to a process for producing PP and/or randomcopolymers of propylene type with lesser formation of lump.US2002/007024 relates to a process for producing polyethylene with aZiegler-Natta type catalyst and ether type external electron donors.U.S. Pat. No. 4,921,919 relates to a process for vapor-phasepolymerization of monomers for minimizing the formation of polymeragglomerates or lumps. Chan et al (“Syntheses and ultraviolet spectra ofN-organosilyl ketimines” J. Organometal. Chem. 1967, vol. 9 no. 2, pp231-250) relates to the synthesis of N-organosilyl ketimines. U.S. Pat.No. 3,622,529 relates to a stable composition comprising silanolchain-stopped polydiorganosiloxanes. CA 957 695 relates to the synthesisof imidatosilanes from imidate and a chlorosilane.

However, by using such external electron donors known in the prior art,high formation of lumps in the powder polymer products within thereactor vessel and in the powder polymer product might occur undercertain circumstances. Polymer chunks or lumps not only hamperproduction, reducing reaction rates and production rates but also inducea greater amount of risks, such as injuries and fire while removingpolymer chunks using normal maintenance practices. In addition, lumps inthe product result in a non-uniform size product and lumps inside thereactor vessel can result in stoppage of the process requiring cleaningof the reactor vessel before the process can be continued. This can bequite costly and time consuming.

There is, therefore, an on-going need in industry for catalysts showingbetter or varied performance in polymerization of olefins withouthampering production of polyolefins.

It is thus an object of the invention to provide an improved catalystsystem having high hydrogen and ethylene response that allows obtainingof a polyolefin, preferably a propylene-based polymer with highisotacticity, while minimizing the formation of polymer agglomerates andlumps in the reactor for making the polyolefin.

SUMMARY OF THE INVENTION

This object is achieved with a catalyst system for polymerization of anolefin comprising a Ziegler-Natta type procatalyst, a co-catalyst and anexternal electron donor, wherein the external electron donor has thestructure according to Formula I′:

Si(L)_(n)(OR¹¹)_(4-n-m)(R¹²)_(m)  Formula I′

wherein,Si is a silicon atom with valency 4+;O is an oxygen atom with valency 2− and O is bonded to Si via asilicon-oxygen bond;n is 1, 2, 3 or 4;m is 0, 1 or 2n+m≦4each R¹¹ group is independently selected from the group consisting oflinear, branched and cyclic alkyl having at most 20 carbon atoms andaromatic substituted and unsubstituted hydrocarbyl having 6 to 20 carbonatoms; andeach R¹² group is independently selected from the group consisting oflinear, branched and cyclic alkyl having at most 20 carbon atoms andaromatic substituted and unsubstituted hydrocarbyl having 6 to 20 carbonatoms;each L group is independently a group represented by the followingstructure

wherein,L is bonded to the silicon atom via a nitrogen-silicon bond;L has a single substituent on the nitrogen atom, where this singlesubstituent is an imine carbon atom; andX and Y are each independently selected from the group consisting of:

-   a) a hydrogen atom;-   b) a group comprising a heteroatom selected from group 13, 14, 15,    16 or 17 of the IUPAC Periodic Table of the Elements, through which    X and Y are each independently bonded to the imine carbon atom of    Formula II, wherein the heteroatom is substituted with a group    consisting of a linear, branched and cyclic alkyl having at most 20    carbon atoms, optionally containing a heteroatom selected from group    13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements;    and/or with an aromatic substituted and unsubstituted hydrocarbyl    having 6 to 20 carbon atoms, optionally containing a heteroatom    selected from group 13, 14, 15, 16 or 17 of the IUPAC Periodic Table    of the Elements;-   c) a linear, branched and cyclic alkyl having at most 20 carbon    atoms, optionally containing a heteroatom selected from group 13,    14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements; and-   d) an aromatic substituted and unsubstituted hydrocarbyl having 6 to    20 carbon atoms, optionally containing a heteroatom selected from    group 13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the    Elements.

In a preferred embodiment, at least one of X and Y is selected from b),c) or d). In other words, in said preferred embodiment, X and Y are notboth hydrogen.

In an embodiment of said catalyst system L is guanidine, amidine orketimide.

In an embodiment of said catalyst system R¹¹ is an alkyl having at most10 carbon atoms.

In another aspect, the present invention relates to a process forpreparing the catalyst system according to the invention, comprisingcontacting a Ziegler-Natta type procatalyst, a co-catalyst and anexternal electron donor comprising the compound according to Formula I′.

In an embodiment, said process comprising the steps of:

-   -   A) providing a Ziegler-Natta procatalyst obtainable via a        process comprising the steps of:        -   i) contacting a compound R⁴ _(z)MgX⁴ _(2-z) with an alkoxy-            or aryloxy-containing silane compound to give a first            intermediate reaction product, being a solid Mg(OR¹)_(x)X¹            _(2-x), wherein: R⁴ is the same as R¹ being a linear,            branched or cyclic hydrocarbyl group independently selected            e.g. from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or            alkylaryl groups, and one or more combinations thereof;            wherein said hydrocarbyl group may be substituted or            unsubstituted, may contain one or more heteroatoms and            preferably has between 1 and 20 carbon atoms; X⁴ and X¹ are            each independently selected from the group of consisting of            fluoride (F—), chloride (Cl—), bromide (Br—) or iodide (I—),            preferably chloride; z is in a range of larger than 0 and            smaller than 2, being 0<z<2;        -   ii) optionally contacting the solid Mg(OR¹)_(x)X¹ _(2-x)            obtained in step i) with at least one activating compound            selected from the group formed of activating electron donors            and metal alkoxide compounds of formula            M¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w), to obtain a            second intermediate product; wherein M¹ is a metal selected            from the group consisting of Ti, Zr, Hf, Al or Si; M² is a            metal being Si; v is the valency of M¹ or M²; R² and R³ are            each a linear, branched or cyclic hydrocarbyl group            independently selected e.g. from alkyl, alkenyl, aryl,            aralkyl, alkoxycarbonyl or alkylaryl groups, and one or more            combinations thereof; wherein said hydrocarbyl group may be            substituted or unsubstituted, may contain one or more            heteroatoms, and preferably has between 1 and 20 carbon            atoms;        -   iii) contacting the first or second intermediate reaction            product, obtained respectively in step i) or ii), with a            halogen-containing Ti-compound and optionally an internal            electron donor to obtain said procatalyst;    -   B) contacting said procatalyst with a co-catalyst and at least        one external electron donor being a compound having the        structure according to Formula I′.

In another embodiment, Mg(OR¹)_(x)X¹ _(2-x) is contacted in step ii)with titanium tetraalkoxide and an alcohol as activating compounds.

In another embodiment, the co-catalyst is a hydrocarbyl aluminumcompound represented by the formula R²¹ _(m)AlX²¹ _(3-m), wherein m=1 or2, R is an alkyl, and X is a halide or alkoxide.

In yet another aspect, the present invention relates to a process forpreparing a polyolefin by contacting at least one olefin with thecatalyst system according to the invention or obtainable by a processfor preparing the catalyst system according to the present invention.

In an embodiment, the at least one olefin is propylene or a mixture ofpropylene and ethylene.

The present invention furthermore relates to a polyolefin obtainable bythe process for preparing a polyolefin according to the invention,wherein the polyolefin has a lump content below 10 wt. %, preferablybelow 4 wt. % and more preferably below 3 wt. %.

In another aspect, the present invention relates to a polyolefin havinga lump content below 10 wt. %, preferably below 4 wt. % and morepreferably below 3 wt. %.

In an embodiment, the polyolefin is a propylene-based polymer. Inanother aspect, the present invention relates to a shaped articlecomprising the polyolefin according to the invention.

In another aspect, the present invention relates to compound having thestructure according to Formula Ia′:

Si(L)_(q)(OR¹¹)_(4-q-m)(R¹²)_(m)  Formula Ia′

wherein,Si is a silicon atom with valency 4+;O is an oxygen atom with valency 2− and O is bonded to Si via thesilicon-oxygen bond;q is 1, 2 or 3;m is 0, 1 or 2on the proviso that when q=3, m=0on the proviso that when q=2, m=0 or 1on the proviso than when q=1, m=0, 1 or 2each R¹¹ group is independently selected from the group consisting oflinear, branched and cyclic alkyl having at most 20 carbon atoms andaromatic substituted and unsubstituted hydrocarbyl having 6 to 20 carbonatoms;each R¹² group is independently selected from the group consisting oflinear, branched and cyclic alkyl having at most 20 carbon atoms andaromatic substituted and unsubstituted hydrocarbyl having 6 to 20 carbonatoms;each L group is independently a group represented by the followingstructure

wherein,L is bonded to the silicon atom via the nitrogen-silicon bond;L has a single substituent on the nitrogen atom, where this singlesubstituent is an imine carbon atom; andX and Y are each independently selected from the group consisting of

-   -   a) a hydrogen atom;    -   b) a group comprising a heteroatom selected from group 13, 14,        15, 16 or 17 of the IUPAC Periodic Table of the Elements,        through which X and Y are each independently bonded to the imine        carbon atom of Formula II, wherein the heteroatom is substituted        with a group consisting of a linear, branched and cyclic alkyl        having at most 20 carbon atoms, optionally containing a        heteroatom selected from group 13, 14, 15, 16 or 17 of the IUPAC        Periodic Table of the Elements; and/or with an aromatic        substituted and unsubstituted hydrocarbyl having 6 to 20 carbon        atoms, optionally containing a heteroatom selected from group        13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the        Elements;    -   c) a linear, branched and cyclic alkyl having at most 20 carbon        atoms, optionally containing a heteroatom selected from group        13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the        Elements; and    -   d) an aromatic substituted and unsubstituted hydrocarbyl having        6 to 20 carbon atoms, optionally containing a heteroatom        selected from group 13, 14, 15, 16 or 17 of the IUPAC Periodic        Table of the Elements.

In a preferred embodiment, at least one of X and Y is selected from b),c) or d). In other words, in said preferred embodiment, X and Y are notboth hydrogen.

In an embodiment, the following is observed: on the proviso than whenq=1, m=2. In an embodiment, the following is observed: on the provisothan when q=2, m=0.

In another aspect, the present invention relates to the use of thecompound having the structure according to Formula I′ or Ia′ as anexternal electron donor in a Ziegler-Natta type catalyst system forpolymerization of an olefin.

The advantage of the present invention is that with the use of theexternal donors according to the present invention an improved catalystsystem is obtained having high hydrogen and ethylene response.

A further advantage of the present invention is that with the presentcatalyst system polypropylene having high isotacticity is obtained.

The external electron donor according to the present invention exhibitshigh compatibility with Ziegler-Natta type procatalyst compositions andcontribute to high catalyst activity, high hydrogen response and highethylene response when combined with the procatalyst and theco-catalyst, while minimizing the formation of polymer agglomerates orlumps in the reactor for making polyolefins, particularly polypropylene.

In addition, the external donors according to the present inventionproduce polyolefins with high isotacticity and high melt flow rates whenused in Ziegler-Natta catalyst systems.

Furthermore, the catalyst system according to the present inventioncomprising the specific external donor according to Formula I′ allowsobtaining of propylene-ethylene copolymers, which have a highisotacticity and high melt flow rate, while the catalyst system exhibitsa high hydrogen and ethylene response, and in the same time minimizingformation of lumps in the reactor.

Moreover, by using the catalyst system according to the presentinvention comprising the special external donor of Formula I′,propylene-ethylene random copolymers having a more random distributionof the ethylene comonomer in the polymer chain can be obtained. Also,the rubber content in a heterophasic polypropylene composition may beincreased by using the catalyst system according to the invention.

DEFINITIONS

The following definitions are used in the present description and claimsto define the stated subject matter. Other terms not cited below aremeant to have the generally accepted meaning in the field.

“Ziegler-Natta catalyst” as used in the present description means: atransition metal-containing solid catalyst compound comprising atransition metal halide selected from titanium halide, chromium halide,hafnium halide, zirconium halide, and vanadium halide, supported on ametal or metalloid compound (e.g. a magnesium compound or a silicacompound).

“Ziegler-Natta catalytic species” or “catalytic species” as used in thepresent description means: a transition metal-containing speciescomprises a transition metal halide selected from titanium halide,chromium halide, hafnium halide, zirconium halide and vanadium halide.

“internal donor” or “internal electron donor” or “ID” as used in thepresent description means: an electron-donating compound containing oneor more atoms of oxygen (O) and/or nitrogen (N). This ID is used as areactant in the preparation of a solid procatalyst. An internal donor iscommonly described in prior art for the preparation of a solid-supportedZiegler-Natta catalyst system for olefins polymerization; i.e. bycontacting a magnesium-containing support with a halogen-containing Ticompound and an internal donor.

“external donor” or “external electron donor” or “ED” as used in thepresent description means: an electron-donating compound used as areactant in the polymerization of olefins. An ED is a compound addedindependent of the procatalyst. It is not added during procatalystformation. It contains at least one functional group that is capable ofdonating at least one pair of electrons to a metal atom. The ED mayinfluence catalyst properties, non-limiting examples thereof areaffecting the stereoselectivity of the catalyst system in polymerizationof olefins having 3 or more carbon atoms, hydrogen sensitivity, ethylenesensitivity, randomness of co-monomer incorporation and catalystproductivity.

“activator” as used in the present description means: anelectron-donating compound containing one or more atoms of oxygen (O)and/or nitrogen (N) which is used during the synthesis of theprocatalyst prior to or simultaneous with the addition of an internaldonor.

“activating compound” as used in the present description means: acompound used to activate the solid support prior to contacting it withthe catalytic species.

“modifier” or “Group 13- or transition metal modifier” as used in thepresent description means: a metal modifier comprising a metal selectedfrom the metals of Group 13 of the IUPAC Periodic Table of elements andtransition metals. Where in the description the terms metal modifier ormetal-based modifier is used, Group 13- or transition metal modifier ismeant.

“procatalyst” and “catalyst component” as used in the presentdescription have the same meaning: a component of a catalyst compositiongenerally comprising a solid support, a transition metal-containingcatalytic species and optionally one or more internal donor.

“halide” as used in the present description means: an ion selected fromthe group of: fluoride (F—), chloride (Cl—), bromide (Br—) or iodide(I—).

“halogen” as used in the present description means: an ion selected fromthe group of: fluorine (F), chlorine (Cl), bromine (Br) or iodine (I).

“heteroatom” as used in the present description means: an atom otherthan carbon or hydrogen. However, as used herein—unless specifiedotherwise, such as below,—when “one or more hetereoatoms” is used one ormore of the following is meant: F, Cl, Br, I, N, O, P, B, S or Si.

“heteroatom selected from group 13, 14, 15, 16 or 17 of the IUPACPeriodic Table of the Elements” as used in the present descriptionmeans: a hetero atom selected from B, Al, Ga, In, Tl [Group 13], Si, Ge,Sn, Pb [Group 14], N, P, As, Sb, Bi [Group 15], O, S, Se, Te, Po [Group16], F, Cl, Br, I, At [Group 17].

“hydrocarbyl” as used in the present description means: is a substituentcontaining hydrogen and carbon atoms, or linear, branched or cyclicsaturated or unsaturated aliphatic radical, such as alkyl, alkenyl,alkadienyl and alkynyl; alicyclic radical, such as cycloalkyl,cycloalkadienyl cycloalkenyl; aromatic radical, such as monocyclic orpolycyclic aromatic radical, as well as combinations thereof, such asalkaryl and aralkyl.

“substituted hydrocarbyl” as used in the present description means: is ahydrocarbyl group that is substituted with one or more non-hydrocarbylsubstituent groups. A non-limiting example of a non-hydrocarbylsubstituent is a heteroatom. Examples are alkoxycarbonyl (viz.carboxylate) groups. When in the present description “hydrocarbyl” isused it can also be “substituted hydrocarbyl”, unless stated otherwise.

“alkyl” as used in the present description means: an alkyl group being afunctional group or side-chain consisting of carbon and hydrogen atomshaving only single bonds. An alkyl group may be straight or branched andmay be un-substituted or substituted. It may or may not containheteroatoms, such as oxygen (O), nitrogen (N), phosphorus (P), silicon(Si) or sulfur (S). An alkyl group also encloses aralkyl groups whereinone or more hydrogen atoms on the alkyl groups have been replaced byaryl groups.

“aryl” as used in the present description means: an aryl group being afunctional group or side-chain derived from an aromatic ring. An arylgroup and may be un-substituted or substituted with straight or branchedhydrocarbyl groups. It may or may not contain heteroatoms, such asoxygen (O), nitrogen (N), phosphorus (P), silicon (Si) or sulfur (S).

An aryl group also encloses alkaryl groups wherein one or more hydrogenatoms on the aromatic ring have been replaced by alkyl groups.

“aralkyl” as used in the present description means: an arylalkyl groupbeing an alkyl group wherein one or more hydrogen atoms have beenreplaced by aryl groups “alkoxide” or “alkoxy” as used in the presentdescription means: a functional group or side-chain obtained from aalkyl alcohol. It consist of an alkyl bonded to a negatively chargedoxygen atom.

“aryloxide” or “aryloxy” or “phenoxide” as used in the presentdescription means: a functional group or side-chain obtained from anaryl alcohol. It consist of an aryl bonded to a negatively chargedoxygen atom.

“Grignard reagent” or “Grignard compound” as used in the presentdescription means: a compound or a mixture of compounds of formula R⁴_(z)MgX⁴ _(2-z) (R⁴, z, and X⁴ are as defined below) or it may be acomplex having more Mg clusters, e.g. R₄Mg₃Cl₂.

“polymer” as used in the present description means: a chemical compoundcomprising repeating structural units, wherein the structural units aremonomers.

“olefin” as used in the present description means: an alkene.

“olefin-based polymer” or “polyolefin” as used in the presentdescription means: a polymer of one or more alkenes.

“propylene-based polymer” as used in the present description means: apolymer of propylene and optionally a comonomer.

“polypropylene” as used in the present description means: a polymer ofpropylene.

“copolymer” as used in the present description means: a polymer preparedfrom two or more different monomers.

“monomer” as used in the present description means: a chemical compoundthat can undergo polymerization.

“thermoplastic” as used in the present description means: capable ofsoftening or fusing when heated and of hardening again when cooled.

“polymer composition” as used in the present description means: amixture of either two or more polymers or of one or more polymers andone or more additives.

“M_(w)” and “M_(n)” in the context of the present invention means theratio of the weight average molecular weight M_(w) and the numberaverage molecular weight M_(n) of a sample, as measured according toASTM D6474-12.

“PDI” in the context of the present invention means the ratio of theweight average molecular weight M_(w) and the number average molecularweight M_(n) of a sample, as measured according to ASTM D6474-12. Asused herein, the terms “PDI” and “polydispersity index” areinterchangeable.

“MWD” in the context of the present invention means distribution of themolecular weight of a sample, as represented by the ratio of the weightaverage molecular weight M_(w) and the number average molecular weightM_(n) of a sample as measured according to ASTM D6474-12. As usedherein, the terms “MWD” and “molecular weight distribution” areinterchangeable.

“XS” as used in the present description means: the xylene solublefraction in terms of percentage of polymer that does not precipitate outupon cooling of a polymer solution in xylene, said polymer solutionhaving been subjected to reflux conditions, down from the refluxtemperature, which equals the boiling temperature of xylene, to 25° C.XS is measured according to ASTM D5492-10. As used herein, the terms“XS” and “xylene soluble fraction” are interchangeable.

“lump content” as used in the present description means: the weightpercentage of the total isolated polymer weight which does not passthrough a sieve having a pore size of 2.8 mm.

“polymerization conditions” as used in the present description means:temperature and pressure parameters within a polymerization reactorsuitable for promoting polymerization between the catalyst compositionand an olefin to form the desired polymer. These conditions depend onthe type of polymerization used.

“production rate” or “yield” as used in the present description means:the amount of kilograms of polymer produced per gram of catalyst systemconsumed in the polymerization reactor per hour, unless statedotherwise.

“MFR” as used in the present description means: the melt mass-flow rateas measured according to ISO 1133:2005, at 230° C. under a load of 2.16kg. As used herein, the terms “MFR”, “melt flow rate” and “meltmass-flow rate” are interchangeable.

“bulk density” in the context of the present invention means the weightper unit volume of a material, including voids inherent in the materialas tested. Bulk density is measured as apparent density according toASTM D1895-96 Reapproved 2010-e1, test method A.

Unless stated otherwise, when it is stated that any R group is“independently selected from” this means that when several of the same Rgroups are present in a molecule they may have the same meaning of theymay not have the same meaning. For example, for the compound R₂M,wherein R is independently selected from ethyl or methyl, both R groupsmay be ethyl, both R groups may be methyl or one R group may be ethyland the other R group may be methyl.

The present invention is described below in more detail. All embodimentsdescribed with respect to one aspect of the present invention are alsoapplicable to the other aspects of the invention, unless otherwisestated.

The present invention is related to Ziegler-Natta type catalysts. AZiegler-Natta type procatalyst generally comprising a solid support, atransition metal-containing catalytic species and optionally one or moreinternal donors. The present invention relates to a catalyst systemcomprising a Ziegler-Natta type procatalyst, a co-catalyst andoptionally an external electron donor. The term “Ziegler-Natta” is knownin the art.

The transition metal-containing solid catalyst compound comprises atransition metal halide (e.g. titanium halide, chromium halide, hafniumhalide, zirconium halide or vanadium halide) supported on a metal ormetalloid compound (e.g. a magnesium compound or a silica compound).

Specific examples of several types of Ziegler-Natta catalyst asdisclosed below.

Preferably, the present invention is related to a so-called TiNocatalyst. It is a magnesium-based supported titanium halide catalystoptionally comprising one or more internal donors.

EP 1 273 595 of Borealis Technology discloses a process for producing anolefin polymerization procatalyst in the form of particles having apredetermined size range, said process comprising: preparing a solutiona complex of a Group IIa metal and an electron donor by reacting acompound of said metal with said electron donor or a precursor thereofin an organic liquid reaction medium; reacting said complex, insolution, with at least one compound of a transition metal to produce anemulsion the dispersed phase of which contains more than 50 mol. % ofthe Group IIa metal in said complex; maintaining the particles of saiddispersed phase within the average size range 10 to 200 μm by agitationin the presence of an emulsion stabilizer and solidifying saidparticles; and recovering, washing and drying said particles to obtainsaid procatalyst.

EP 0 019 330 of Dow discloses a Ziegler-Natta type catalyst composition.Said olefin polymerization catalyst composition comprising: a) areaction product of an organo aluminum compound and an electron donor,and b) a solid component which has been obtained by halogenating amagnesium compound with the formula MgR¹R² wherein R¹ is an alkyl, aryl,alkoxide or aryloxide group and R² is an alkyl, aryl, alkoxide oraryloxide group or halogen, with a halide of tetravalent titanium in thepresence of a halohydrocarbon, and contacting the halogenated productwith a tetravalent titanium compound. This production method asdisclosed in EP 0 019 330 is incorporated by reference.

The Examples of U.S. Pat. No. 5,093,415 of Dow discloses an improvedprocess to prepare a catalyst. Said process includes a reaction betweentitanium tetrachloride, diisobutyl phthalate, and magnesium diethoxideto obtain a solid material. This solid material is then slurried withtitanium tetrachloride in a solvent and phthaloyl chloride is added. Thereaction mixture is heated to obtain a solid material which isreslurried in a solvent with titanium tetrachloride. Again this washeated and a solid collected. Once again the solid was reslurried onceagain in a solution of titanium tetrachloride to obtain a catalyst. TheExamples of U.S. Pat. No. 5,093,415 are incorporated by reference.

Example 2 of U.S. Pat. No. 6,825,146 of Dow discloses another improvedprocess to prepare a catalyst. Said process includes a reaction betweentitanium tetrachloride in solution with a precursor composition—preparedby reacting magnesium diethoxide, titanium tetraethoxide, and titaniumtetrachloride, in a mixture of ortho-cresol, ethanol andchlorobenzene—and ethylbenzoate as electron donor. The mixture washeated and a solid was recovered. To the solid titanium tetrachloride, asolvent and benzoylchloride were added. The mixture was heated to obtaina solid product. The last step was repeated. The resulting solidprocatalyst was worked up to provide a catalyst. Example 2 of U.S. Pat.No. 6,825,146 is incorporated by reference.

U.S. Pat. No. 4,771,024 discloses the preparation of a catalyst oncolumn 10, line 61 to column 11, line 9. The section “catalystmanufacture on silica” is incorporated into the present application byreference. The process comprises combining dried silica with carbonatedmagnesium solution (magnesium diethoxide in ethanol was bubbled withCO₂). The solvent was evaporated at 85° C. The resulting solid waswashed and a 50:50 mixture of titanium tetrachloride and chlorobenzenewas added to the solvent together with ethylbenzoate. The mixture washeated to 100° C. and liquid filtered. Again TiCl₄ and chlorobenzenewere added, followed by heating and filtration. A final addition ofTiCl₄ and chlorobenzene and benzoylchloride was carried out, followed byheating and filtration. After washing the catalyst was obtained.

WO03/068828 discloses a process for preparing a catalyst component onpage 91 “preparation of solid catalyst components” which section isincorporated into the present application by reference. Magnesiumchloride, toluene, epoxy chloropropane and tributyl phosphate were addedunder nitrogen to a reactor, followed by heating. Then phthalicanhydride was added. The solution was cooled to −25° C. and TiCl₄ wasadded drop wise, followed by heating. An internal donor was added(1,3-diphenyl-1,3-propylene glycol dibenzoate,2-methyl-1,3-diphenyl-1,3-propylene glycol dibenzoate,1,3-diphenyl-1,3-propylene-glycol diproprionate, or1,3-diphenyl-2-methyl-1,3-propylene glycol diproprionate) and afterstirring a solid was obtained and washed. The solid was treated withTiCl₄ in toluene twice, followed by washing to obtain said catalystcomponent.

U.S. Pat. No. 4,866,022 discloses a catalyst component comprises aproduct formed by: A. forming a solution of a magnesium-containingspecies from a magnesium carbonate or a magnesium carboxylate; B.precipitating solid particles from such magnesium-containing solution bytreatment with a transition metal halide and an organosilane having aformula: R_(n)SiR′_(4-n), wherein n=0 to 4 and wherein R is hydrogen oran alkyl, a haloalkyl or aryl radical containing one to about ten carbonatoms or a halosilyl radical or haloalkylsilyl radical containing one toabout eight carbon atoms, and R′ is OR or a halogen: C. re-precipitatingsuch solid particles from a mixture containing a cyclic ether; and D.treating the re-precipitated particles with a transition metal compoundand an electron donor. This process for preparing a catalyst isincorporated into the present application by reference.

The present invention also relates to a catalyst system comprising aZiegler-Natta type procatalyst, a co-catalyst and the external electrondonor of Formula Ia′, as defined herein; and to a process to make apolyolefin by contacting an olefin with the catalyst system comprisingthe compound of Formula Ia′ as external donor. Furthermore, the compoundof Formula Ia′ can be used as an external electron donor in aZiegler-Natta type catalyst system for polymerization of an olefin.

The procatalyst may be produced by any method known in the art.

The procatalyst may also be produced as disclosed in WO96/32426A; thisdocument discloses a process for the polymerization of propylene using acatalyst comprising a catalyst component obtained by a process wherein acompound with formula Mg(OAlk)_(x)Cl_(y) wherein x is larger than 0 andsmaller than 2, y equals 2-x and each Alk, independently, represents analkyl group, is contacted with a titanium tetraalkoxide and/or analcohol in the presence of an inert dispersant to give an intermediatereaction product and wherein the intermediate reaction product iscontacted with titanium tetrachloride in the presence of an internaldonor, which is di-n-butyl phthalate (DBP).

Preferably, the Ziegler-Natta type procatalyst in the catalyst systemaccording to the present invention is obtained by the process asdescribed in WO 2007/134851 A1. In Example I the process is disclosed inmore detail. Example I including all sub-examples (IA-IE) of WO2007/134851 A1 is incorporated into the present description. Moredetails about the different embodiments are disclosed starting on page3, line 29 to page 14 line 29 of WO 2007/134851 A1. These embodimentsare incorporated by reference into the present description.

In the following part of the description the different steps and phasesof the process for preparing the procatalyst for use in an embodiment ofthe catalyst system according to the present invention will bediscussed.

The process for preparing a procatalyst used in an embodiment accordingto the present invention comprises the following phases:

-   -   Phase A): preparing a solid support for the procatalyst;    -   Phase B): optionally activating said solid support obtained in        phase A) using one or more activating compounds to obtain an        activated solid support;    -   Phase C): contacting said solid support obtained in phase A) or        said activated solid support in phase B) with a catalytic        species wherein phase C) comprises one of the following:        -   contacting said solid support obtained in phase A) or said            activated solid support in phase B) with a catalytic species            to obtain said procatalyst; or        -   contacting said solid support obtained in phase A) or said            activated solid support in phase B) with a catalytic species            and one or more internal donors to obtain said procatalyst;            or        -   contacting said solid support obtained in phase A) or said            activated solid support in phase B) with a catalytic species            and one or more internal donors to obtain an intermediate            product; or        -   contacting said solid support obtained in phase A) or said            activated solid support in phase B) with a catalytic species            and an activator to obtain an intermediate product;    -   optionally Phase D: modifying said intermediate product obtained        in phase C) wherein phase D) comprises on of the following:        -   modifying said intermediate product obtained in phase C)            with a Group 13- or transition metal modifier in case an            internal donor was used during phase C), in order to obtain            a procatalyst;        -   modifying said intermediate product obtained in phase C)            with a Group 13- or transition metal modifier and one or            more internal donors in case an activator was used during            phase C), in order to obtain a procatalyst.

The procatalyst thus prepared may be used in polymerization of olefinsas part of a catalyst system together with an external donor and aco-catalyst.

The various steps used to prepare the procatalyst that might be part ofthe catalyst system according to the present invention are described inmore detail below.

Phase A: Preparing a Solid Support for the Procatalyst

In an embodiment of the process for preparing a catalyst systempreferably a magnesium-containing support is used. Saidmagnesium-containing support is known in the art as a typical componentof a Ziegler-Natta procatalyst. The following description explains theprocess of preparing a magnesium-based support. Other supports may beused.

Synthesis of magnesium-containing supports, such as magnesium halides,magnesium alkyls and magnesium aryls, and also magnesium alkoxy andmagnesium aryloxy compounds for polyolefin production, particularly ofpolypropylenes production are described for instance in U.S. Pat. No.4,978,648, WO96/32427A1, WO01/23441 Al, EP1283 222A1, EP1222 214B1; U.S.Pat. No. 5,077,357; U.S. Pat. No. 5,556,820; U.S. Pat. No. 4,414,132;U.S. Pat. No. 5,106,806 and U.S. Pat. No. 5,077,357 but the presentprocess is not limited to the disclosure in these documents.

Preferably, the process for preparing the solid support for theprocatalyst used in an embodiment according to the present inventioncomprises the following steps: step o) which is optional and step i).

Step o) Preparation of the Grignard Reagent (Optional)

A Grignard reagent, R⁴ _(z)MgX⁴ _(2-z) used in step i) may be preparedby contacting metallic magnesium with an organic halide R⁴X⁴, asdescribed in WO 96/32427 A1 and WO01/23441 A1. All forms of metallicmagnesium may be used, but preferably use is made of finely dividedmetallic magnesium, for example magnesium powder. To obtain a fastreaction it is preferable to heat the magnesium under nitrogen prior touse.

R⁴ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkylaryl, or alkoxycarbonyl groups, whereinsaid hydrocarbyl group may be linear, branched or cyclic, and may besubstituted or unsubstituted; said hydrocarbyl group preferably havingfrom 1 to 20 carbon atoms or combinations thereof. The R⁴ group maycontain one or more heteroatoms.

X⁴ is selected from the group of consisting of fluoride (F—), chloride(Cl—), bromide (Br—) or iodide (I—). The value for z is in a range oflarger than 0 and smaller than 2: 0<z<2

Combinations of two or more organic halides R⁴X⁴ can also be used.

The magnesium and the organic halide R⁴X⁴ can be reacted with each otherwithout the use of a separate dispersant; the organic halide R⁴X⁴ isthen used in excess.

The organic halide R⁴X⁴ and the magnesium can also be brought intocontact with one another and an inert dispersant. Examples of thesedispersants are: aliphatic, alicyclic or aromatic dispersants containingfrom 4 up to 20 carbon atoms.

Preferably, in this step o) of preparing R⁴ _(z)MgX⁴ _(2-z), also anether is added to the reaction mixture. Examples of suitable ethers are:diethyl ether, diisopropyl ether, dibutyl ether, diisobutyl ether,diisoamyl ether, diallyl ether, tetrahydrofuran and anisole. Dibutylether and/or diisoamyl ether are preferably used. Preferably, an excessof chlorobenzene is used as the organic halide R⁴X⁴. Thus, thechlorobenzene serves as dispersant as well as organic halide R⁴X⁴.

The organic halide/ether ratio acts upon the activity of theprocatalyst. The chlorobenzene/dibutyl ether volume ratio may forexample vary from 75:25 to 35:65, preferably from 70:30 to 50:50.

Small amounts of iodine and/or alkyl halides can be added to cause thereaction between the metallic magnesium and the organic halide R⁴X⁴ toproceed at a higher rate. Examples of alkyl halides are butyl chloride,butyl bromide and 1,2-dibromoethane. When the organic halide R⁴X⁴ is analkyl halide, iodine and 1,2-dibromoethane are preferably used.

The reaction temperature for step o) of preparing R⁴ _(z)MgX⁴ _(2-z) maybe from 20 to 150° C.; the reaction time may be from 0.5 to 20 hours.After the reaction for preparing R⁴ _(z)MgX⁴ _(2-z) is completed, thedissolved reaction product may be separated from the solid residualproducts. The reaction may be mixed. The stirring speed can bedetermined by a person skilled in the art and should be sufficient toagitate the reactants.

Step i) Reacting a Grignard Compound with a Silane Compound

Step i): contacting a compound R⁴ _(z)MgX⁴ _(2-z)— wherein R₄, X⁴, and zare as discussed above—with an alkoxy- or aryloxy-containing silanecompound to give a first intermediate reaction product. Said firstintermediate reaction product is a solid magnesium-containing support.It should be noted that with “alkoxy- or aryloxy-containing” is meantOR¹ containing. In other words said alkoxy- or aryloxy-containing silanecompound comprises at least one OR¹ group. R¹ is selected from the groupconsisting of a linear, branched or cyclic hydrocarbyl groupindependently selected e.g. from alkyl, alkenyl, aryl, aralkyl,alkoxycarbonyl or alkylaryl groups, and one or more combinationsthereof; wherein said hydrocarbyl group may be substituted orunsubstituted, may contain one or more heteroatoms and preferably hasfrom 1 to 20 carbon atoms.

In step i) a first intermediate reaction product is thus prepared bycontacting the following reactants: * a Grignard reagent—being acompound or a mixture of compounds of formula R⁴ _(z)MgX⁴ _(2-z) and *an alkoxy- or aryloxy-containing silane compound. Examples of thesereactants are disclosed for example in WO 96/32427 A1 and WO01/23441 A1.

The compound R⁴ _(z)MgX⁴ _(2-z) used as starting product is alsoreferred to as a Grignard compound. In R⁴ _(z)MgX⁴ _(2-z), X⁴ ispreferably chloride or bromide, more preferably chloride.

R⁴ can be an alkyl, aryl, aralkyl, alkoxide, phenoxide, etc., ormixtures thereof. Suitable examples of group R⁴ are methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, hexyl, cyclohexyl, octyl,phenyl, tolyl, xylyl, mesityl, benzyl, phenyl, naphthyl, thienyl,indolyl. In a preferred embodiment of the invention, R⁴ represents anaromatic group, for instance a phenyl group.

Preferably, as Grignard compound R⁴ _(z)MgX⁴ _(2-z) used in step i) aphenyl Grignard or a butyl Grignard is used. The selection for eitherthe phenyl Grignard or the butyl Grignard depends on the requirements.

When a Grignard compound is used, a compound according to the formula R⁴_(z)MgX⁴ _(2-z) is meant. When phenyl Grignard is used a compoundaccording to the formula R⁴ _(z)MgX⁴ _(2-z) wherein R⁴ is phenyl, e.g.PhMgCl, is meant. When butyl Grignard is used, a compound according tothe formula R⁴ _(z)MgX⁴ _(2-z) wherein R⁴ is butyl, e.g. BuMgCl orn-BuMgCl, is meant.

An advantage of the use of phenyl Grignard are that it is more activethat butyl Grignard. Preferably, when butyl Grignard is used, anactivation step using an aliphatic alcohol, such as methanol is carriedout in order to increase the activity. Such an activation step may notbe required with the use of phenyl Grignard. A disadvantage of the useof phenyl Grignard is that benzene rest products may be present and thatit is more expensive and hence commercially less interesting.

An advantage of the use of butyl Grignard is that it is benzene free andis commercially more interesting due to the lower price. A disadvantageof the use of butyl Grignard is that in order to have a high activity,an activation step is required.

The process to prepare the procatalyst for use in an embodiment of thepresent invention can be carried out using any Grignard compound, butthe two stated above are the two that are most preferred.

In the Grignard compound of formula R⁴ _(z)MgX⁴ _(2-z) z is preferablyfrom about 0.5 to 1.5.

The compound R⁴ _(z)MgX⁴ _(2-z) may be prepared in an optional step(step o) which is discussed above), preceding step i) or may be obtainedfrom a different process.

It is explicitly noted that it is possible that the Grignard compoundused in step i) may alternatively have a different structure, forexample, may be a complex. Such complexes are already known to theskilled person in the art; a particular example of such complexes isPhenyl₄Mg₃Cl₂.

The alkoxy- or aryloxy-containing silane used in step i) is preferably acompound or a mixture of compounds with the general formula Si(OR⁵)_(4-n) R⁶ _(n),

Wherein it should be noted that the R⁵ group is the same as the R¹group. The R¹ group originates from the R⁵ group during the synthesis ofthe first intermediate reaction product.

R⁵ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 20 carbonatoms, more preferably from 1 to 12 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms. Preferably, said hydrocarbyl group is an alkylgroup, preferably having from 1 to 20 carbon atoms, more preferably from1 to 12 carbon atoms, even more preferably from 1 to 6 carbon atoms,such as for example methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, iso-butyl, t-butyl, pentyl or hexyl; most preferably,selected from ethyl and methyl.

R⁶ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 20 carbonatoms, more preferably from 1 to 12 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms. Preferably, said hydrocarbyl group is an alkylgroup, preferably having from 1 to 20 carbon atoms, more preferably from1 to 12 carbon atoms, even more preferably from 1 to 6 carbon atoms,such as for example methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, iso-butyl, t-butyl, or cyclopentyl.

The value for n is in the range of 0 up to 4, preferably n is from 0 upto and including 1.

Examples of suitable silane-compounds include tetramethoxysilane,tetraethoxysilane, methyltrimethoxysilane, methyltributoxysilane,phenyltriethoxy-silane, diethyldiphenoxysilane, n-propyltriethoxysilane,diisopropyldi-methoxysilane, diisobutyldimethoxysilane,n-propyltrimethoxysilane, cyclohexyl-methyldimethoxysilane,dicyclopentyldimethoxy-silane, isobutylisopropyldimethoxyl-silane,phenyl-trimethoxysilane, diphenyl-dimethoxysilane,trifluoropropylmethyl-dimethoxysilane,bis(perhydroisoquinolino)-dimethoxysilane, dicyclohexyldimethoxy-silane,dinorbornyl-dimethoxysilane, di(n-propyl)dimethoxysilane,di(iso-propyl)-dimethoxysilane, di(n-butyl)dimethoxysilane and/ordi(iso-butyl)dimethoxysilane.

Preferably, tetra ethoxysilane is used as silane-compound in preparingthe solid Mg-containing compound during step i) in the process accordingto the present invention.

Preferably, in step i) the silane-compound and the Grignard compound areintroduced simultaneously to a mixing device to result in particles ofthe first intermediate reaction product having advantageous morphology.This is for example described in WO 01/23441 A1. Here, ‘morphology’ doesnot only refer to the shape of the particles of the solid Mg-compoundand the catalyst made therefrom, but also to the particle sizedistribution (also characterized as span, viz. an indicator for thewidth of the particle size distribution as measured according to ISO13320:2009), its fines content, powder flowability, and the bulk densityof the catalyst particles. Moreover, it is well known that a polyolefinpowder produced in polymerization process using a catalyst system basedon such procatalyst has a similar morphology as the procatalyst (theso-called “replica effect”; see for instance S. van der Ven,Polypropylene and other Polyolefins, Elsevier 1990, p. 8-10).Accordingly, almost round polymer particles are obtained with alength/diameter ratio (I/D) smaller than 2 and with good powderflowability.

As discussed above, the reactants are preferably introducedsimultaneously. With “introduced simultaneously” is meant that theintroduction of the Grignard compound and the silane-compound is done insuch way that the molar ratio Mg/Si does not substantially vary duringthe introduction of these compounds to the mixing device, as describedin WO 01/23441 A1.

The silane-compound and Grignard compound can be continuously orbatch-wise introduced to the mixing device. Preferably, both compoundsare introduced continuously to a mixing device.

The mixing device can have various forms; it can be a mixing device inwhich the silane-compound is premixed with the Grignard compound, themixing device can also be a stirred reactor, in which the reactionbetween the compounds takes place. The separate components may be dosedto the mixing device by means of peristaltic pumps.

Preferably, the compounds are premixed before the mixture is introducedto the reactor for step i). In this way, a procatalyst is formed with amorphology that leads to polymer particles with the best morphology(high bulk density, narrow particle size distribution, (virtually) nofines, excellent flowability).

The Si/Mg molar ratio during step i) may range from 0.2 to 20.Preferably, the Si/Mg molar ratio is from 0.4 to 1.0.

The period of premixing of the reactants in above indicated reactionstep may vary between wide limits, for instance 0.1 to 300 seconds.Preferably, premixing is performed during 1 to 50 seconds.

The temperature during the premixing step of the reactants is notspecifically critical, and may for instance range from 0° C. to 80° C.;preferably the temperature is from 10° C. to 50° C.

The reaction between said reactants may, for instance, take place at atemperature from −20° C. to 100° C.; for example at a temperature offrom 0° C. to 80° C. The reaction time is for example from 1 to 5 hours.

The mixing speed during the reaction depends on the type of reactor usedand the scale of the reactor used. The mixing speed can be determined bya person skilled in the art. As a non-limiting example, mixing may becarried out at a mixing speed of from 250 to 300 rpm. In an embodiment,when a blade stirrer is used the mixing speed is from 220 to 280 rpm andwhen a propeller stirrer is used the mixing speed is from 270 to 330rpm. The stirrer speed may be increased during the reaction. Forexample, during the dosing, the speed of stirring may be increased everyhour by 20-30 rpm.

The first intermediate reaction product obtained from the reactionbetween the silane compound and the Grignard compound is usuallypurified by decanting or filtration followed by rinsing with an inertsolvent, for instance a hydrocarbon solvent with for example 1-20 carbonatoms, like pentane, iso-pentane, hexane or heptane. The solid productcan be stored and further used as a suspension in said inert solvent.Alternatively, the product may be dried, preferably partly dried, andpreferably under mild conditions; e.g. at ambient temperature andpressure.

The first intermediate reaction product obtained by this step i) maycomprise a compound of the formula Mg(OR¹)_(x)X¹ _(2-x), wherein:

R¹ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 20 carbonatoms, more preferably from 1 to 12 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms. Preferably, said hydrocarbyl group is an alkylgroup, preferably having from 1 to 20 carbon atoms, more preferably from1 to 12 carbon atoms, even more preferably from 1 to 6 carbon atoms.Most preferably selected from ethyl and methyl.

X¹ is selected from the group of consisting of fluoride (F—), chloride(Cl—), bromide (Br—) or iodide (I—). Preferably, X¹ is chloride orbromine and more preferably, X¹ is chloride.

The value for x is in the range of larger than 0 and smaller than 2:0<z<2. The value for x is preferably from 0.5 to 1.5.

Phase B: Activating Said Solid Support for the Catalyst

This step of activating said solid support for the catalyst is anoptional step that is not required, but is preferred, in the presentinvention. If this step of activation is carried out, preferably, theprocess for activating said solid support comprises the following stepii). This phase may comprise one or more stages.

Step ii) Activation of the Solid Magnesium Compound

Step ii): contacting the solid Mg(OR¹)_(x)X¹ _(2-x) with at least oneactivating compound selected from the group formed by activatingelectron donors and metal alkoxide compounds of formulaM¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w), wherein:

R² is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 20 carbonatoms, more preferably from 1 to 12 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms. Preferably, said hydrocarbyl group is an alkylgroup, preferably having from 1 to 20 carbon atoms, more preferably from1 to 12 carbon atoms, even more preferably from 1 to 6 carbon atoms,such as for example methyl, ethyl, n-propyl, isopropyl, n-butyl,sec-butyl, iso-butyl, t-butyl, pentyl or hexyl; most preferably selectedfrom ethyl and methyl.

R³ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 20 carbonatoms, more preferably from 1 to 12 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms. Preferably, said hydrocarbyl group is an alkylgroup, preferably having from 1 to 20 carbon atoms, more preferably from1 to 12 carbon atoms, even more preferably from 1 to 6 carbon atoms;most preferably selected from methyl, ethyl, n-propyl, isopropyl,n-butyl, sec-butyl, iso-butyl, t-butyl, and cyclopentyl.

M¹ is a metal selected from the group consisting of Ti, Zr, Hf, Al orSi; v is the valency of M¹; M² is a metal being Si; v is the valency ofM² and w is smaller than v.

The electron donors and the compounds of formula M(OR²)_(v-w)(OR³)_(w)and M(OR²)_(v-w)(R³)_(w) may be also referred herein as activatingcompounds.

In this step either one or both types of activating compounds (viz.activating electron donor or metal alkoxides) may be used.

The advantage of the use of this activation step prior to contacting thesolid support with the halogen-containing titanium compound (processphase C) is that a higher yield of polyolefins is obtained per gram ofthe procatalyst. Moreover, the ethylene sensitivity of the catalystsystem in the copolymerization of propylene and ethylene is alsoincreased because of this activation step. This activation step isdisclosed in detail in WO2007/134851 of the present applicant.

Examples of suitable activating electron donors that may be used in stepii) are known to the skilled person and described herein below, i.e.include carboxylic acids, carboxylic acid anhydrides, carboxylic acidesters, carboxylic acid halides, alcohols, ethers, ketones, amines,amides, nitriles, aldehydes, alkoxides, sulfonamides, thioethers,thioesters and other organic compounds containing one or more heteroatoms, such as nitrogen, oxygen, sulfur and/or phosphorus.

Preferably, an alcohol is used as the activating electron donor in stepii). More preferably, the alcohol is a linear or branched aliphatic oraromatic alcohol having 1-12 carbon atoms. Even more preferably, thealcohol is selected from methanol, ethanol, butanol, isobutanol,hexanol, xylenol and benzyl alcohol. Most preferably, the alcohol isethanol or methanol, preferably ethanol.

Suitable carboxylic acids for use as activating electron donor may bealiphatic or (partly) aromatic. Examples include formic acid, aceticacid, propionic acid, butyric acid, isobutanoic acid, acrylic acid,methacrylic acid, maleic acid, fumaric acid, tartaric acid,cyclohexanoic monocarboxylic acid, cis-1,2-cyclohexanoic dicarboxylicacid, phenylcarboxylic acid, toluenecarboxylic acid, naphthalenecarboxylic acid, phthalic acid, isophthalic acid, terephthalic acidand/or trimellitic acid.

Anhydrides of the aforementioned carboxylic acids can be mentioned asexamples of carboxylic acid anhydrides, such as for example acetic acidanhydride, butyric acid anhydride and methacrylic acid anhydride.

Suitable examples of esters of above-mentioned carboxylic acids areformates, for instance, butyl formate; acetates, for instance ethylacetate and butyl acetate; acrylates, for instance ethyl acrylate,methyl methacrylate and isobutyl methacrylate; benzoates, for instancemethylbenzoate and ethylbenzoate; methyl-p-toluate; ethyl-naphthate andphthalates, for instance monomethyl phthalate, dibutyl phthalate,diisobutyl phthalate, diallyl phthalate and/or diphenyl phthalate.

Examples of suitable carboxylic acid halides for use as activatingelectron donors are the halides of the carboxylic acids mentioned above,for instance acetyl chloride, acetyl bromide, propionyl chloride,butanoyl chloride, butanoyl iodide, benzoyl bromide, p-toluyl chlorideand/or phthaloyl dichloride.

Suitable alcohols are linear or branched aliphatic alcohols with 1-12C-atoms, or aromatic alcohols. Examples include methanol, ethanol,butanol, isobutanol, hexanol, xylenol and benzyl alcohol. The alcoholsmay be used alone or in combination. Preferably, the alcohol is ethanolor hexanol.

Examples of suitable ethers are diethers, such as2-ethyl-2-butyl-1,3-dimethoxypropane,2-isopropyl-2-isopentyl-1,3-dimethoxypropane and/or9,9-bis(methoxymethyl) fluorene. Also, cyclic ethers liketetrahydrofuran (THF), or tri-ethers can be used.

Suitable examples of other organic compounds containing a heteroatom foruse as activating electron donor include 2,2,6,6-tetramethyl piperidine,2,6-dimethylpiperidine, pyridine, 2-methylpyridine, 4-methylpyridine,imidazole, benzonitrile, aniline, diethylamine, dibutylamine,dimethylacetamide, thiophenol, 2-methyl thiophene, isopropyl mercaptan,diethylthioether, diphenylthioether, tetrahydrofuran, dioxane,dimethylether, diethylether, anisole, acetone, triphenylphosphine,triphenylphosphite, diethylphosphate and/or diphenylphosphate.

Examples of suitable metal alkoxides for use in step ii) are metalalkoxides of formulas: M¹(OR²)_(v-w)(OR³)_(w) and M²(OR²)_(v-w)(R³)_(w)wherein M¹, M², R², R³, v, and w are as defined herein. R² and R³ canalso be aromatic hydrocarbon groups, optionally substituted with e.g.alkyl groups and can contain for example from 6 to 20 carbon atoms. TheR² and R³ preferably comprise 1-12 or 1-8 carbon atoms. In preferredembodiments R² and R³ are ethyl, propyl or butyl; more preferably allgroups are ethyl groups.

Preferably, M¹ in said activating compound is Ti or Si. Si-containingcompounds suitable as activating compounds are the same as listed abovefor step i).

The value of w is preferably 0, the activating compound being forexample a titanium tetraalkoxide containing 4-32 carbon atoms in totalfrom four alkoxy groups. The four alkoxide groups in the compound may bethe same or may differ independently. Preferably, at least one of thealkoxy groups in the compound is an ethoxy group. More preferably, thecompound is a tetraalkoxide, such as titanium tetraethoxide.

In the preferred process to prepare the procatalyst according to thisembodiment of the present invention, one activating compound can beused, but also a mixture of two or more compounds may be used.

A combination of a compound of M¹(OR²)_(v-w)(OR³)_(w) orM²(OR²)_(v-w)(R³)_(w) with an electron donor is preferred as activatingcompound to obtain a catalyst system that for example shows highactivity, and of which the ethylene sensitivity can be affected byselecting the internal donor; which is specifically advantageous inpreparing copolymers of for example propylene and ethylene.

Preferably, a Ti-based compound, for example titanium tetraethoxide, isused together with an alcohol, like ethanol or hexanol, or with an estercompound, like ethylacetate, ethylbenzoate or a phthalate ester, ortogether with an ether, like dibutylether, or with pyridine.

If two or more activating compounds are used in step ii) their order ofaddition is not critical, but may affect catalyst performance dependingon the compounds used. A skilled person may optimize their order ofaddition based on some experiments. The compounds of step ii) can beadded together or sequentially.

Preferably, an electron donor compound is first added to the compoundwith formula Mg(OR¹)_(x)X¹ _(2-x) where after a compound of formulaM¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w) as defined herein isadded. The activating compounds preferably are added slowly, forinstance during a period of 0.1-6, preferably during 0.5-4 hours, mostpreferably during 1-2.5 hours, each.

The first intermediate reaction product that is obtained in step i) canbe contacted—when more than one activating compound is used—in anysequence with the activating compounds. In one embodiment, an activatingelectron donor is first added to the first intermediate reaction productand then the compound M¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w) isadded; in this order no agglomeration of solid particles is observed.The compounds in step ii) are preferably added slowly, for instanceduring a period of 0.1-6, preferably during 0.5-4 hours, most preferablyduring 1-2.5 hours, each.

The molar ratio of the activating compound to Mg(OR¹)_(x)X¹ _(2-x) mayrange between wide limits and is, for instance, from 0.02 to 1.0.Preferably, the molar ratio is from 0.05 to 0.5, more preferably from0.06 to 0.4, or even from 0.07 to 0.2.

The temperature in step ii) can be in the range from −20° C. to 70° C.,preferably from −10° C. to 50° C., more preferably in the range from −5°C. to 40° C., and most preferably in the range from 0° C. to 30° C.

Preferably, at least one of the reaction components is dosed in time,for instance during 0.1 to 6, preferably during 0.5 to 4 hours, moreparticularly during 1-2.5 hours.

The reaction time after the activating compounds have been added ispreferably from 0 to 3 hours.

The mixing speed during the reaction depends on the type of reactor usedand the scale of the reactor used. The mixing speed can be determined bya person skilled in the art and should be sufficient to agitate thereactants.

The inert dispersant used in step ii) is preferably a hydrocarbonsolvent. The dispersant may be for example an aliphatic or aromatichydrocarbon with 1-20 carbon atoms.

Preferably, the dispersant is an aliphatic hydrocarbon, more preferablypentane, iso-pentane, hexane or heptane, heptane being most preferred.

Starting from a solid Mg-containing product of controlled morphologyobtained in step i), said morphology is not negatively affected duringtreatment with the activating compound during step ii). The solid secondintermediate reaction product obtained in step ii) is considered to bean adduct of the Mg-containing compound and the at least one activatingcompound as defined in step ii), and is still of controlled morphology.

The obtained second intermediate reaction product after step ii) may bea solid and may be further washed, preferably with the solvent also usedas inert dispersant; and then stored and further used as a suspension insaid inert solvent. Alternatively, the product may be dried, preferablypartly dried, preferably slowly and under mild conditions; e.g. atambient temperature and pressure.

Phase C: Contacting Said Solid Support with the Catalytic Species andOptionally One or More Internal Donors and/or an Activator.

Phase C: contacting the solid support with a catalytic species. Thisstep can take different forms, such as i) contacting said solid supportwith a catalytic species to obtain said procatalyst; ii) contacting saidsolid support with the catalytic species and one or more internal donorsto obtain said procatalyst; iii) contacting said solid support with acatalytic species and one or more internal donors to obtain anintermediate product; iv) contacting the solid support with a catalyticspecies and an activator donor to obtain an intermediate product.

The contacting of the solid support with the catalytic species maycomprise several stages (e.g. I, II and/or III). During each of theseconsecutive stages the solid support is contacted with said catalyticspecies. In other words, the addition or reaction of said catalyticspecies may be repeated one or more times. The same or differentcatalytic species may be used during these stages.

These stages may be divided over Phase C (e.g. step iii) and Phase D(e.g. step v) or step v-a) and v-b). It is possible that Phase Ccomprises one or more stages and that Phase D comprises also one or morestages.

For example, during stage I in phase C (step iii) the solid support(first intermediate) or the activated solid support (secondintermediate) is first contacted with said catalytic species andoptionally subsequently with one or more internal donors and optionallyan activator. When a second stage is present, during stage II (eitherPhase C or Phase D) the intermediate product obtained from stage I willbe contacted with additional catalytic species which may the same ordifferent than the catalytic species added during the first stage andoptionally one or more internal donors and optionally an activator.

In case three stages are present, in an embodiment, stage III is v) ofPhase D which is preferably a repetition of stage I or may comprise thecontacting of the product obtained from phase II with both a catalyticspecies (which may be the same or different as above) and one or moreinternal donors. In other words, an internal donor may be added duringeach of these stages or during two or more of these stages. When aninternal donor is added during more than one stage it may be the same ora different internal donor. In an embodiment stage I is step iii) ofPhase C, stage II is step v-a) of Phase D, and stage III is step v-b) ofPhase D.

An activator according to the present invention—if used—may be addedeither during stage I or stage II or stage III. An activator may also beadded during more than one stage.

Preferably, the process of contacting said solid support with thecatalytic species and an internal donor comprises the following stepiii).

Step iii) Reacting the Solid Support with a Transition Metal Halide

Step iii) reacting the solid support with a transition metal halide(e.g. a halide of titanium, chromium, hafnium, zirconium or vanadium)but preferably titanium halide. In the discussion below only the processfor a titanium-base Ziegler-Natta procatalyst is disclosed, however, thepresent invention is also applicable to other types of Ziegler-Nattaprocatalysts.

Step iii): contacting the first or second intermediate reaction product,obtained respectively in step i) or ii), with a halogen-containingTi-compound and optionally an internal electron donor or activator toobtain a third intermediate product.

Step iii) can be carried out after step i) on the first intermediateproduct or after step ii) on the second intermediate product.

The molar ratio in step iii) of the transition metal to the magnesiumpreferably is from 10 to 100, most preferably, from 10 to 50.

Preferably, an internal electron donor is also present during step iii).Also mixtures of internal electron donors can be used. Examples ofinternal electron donors are disclosed below.

The molar ratio of the internal electron donor relative to the magnesiummay vary between wide limits, for instance from 0.02 to 0.75.Preferably, this molar ratio is from 0.05 to 0.4; more preferably from0.1 to 0.4; and most preferably from 0.1 to 0.3.

During contacting the first or second intermediate product and thehalogen-containing titanium compound, an inert dispersant is preferablyused. The dispersant preferably is chosen such that virtually all sideproducts formed are dissolved in the dispersant. Suitable dispersantsinclude for example aliphatic and aromatic hydrocarbons and halogenatedaromatic solvents with for instance 4-20 carbon atoms. Examples includetoluene, xylene, benzene, heptane, o-chlorotoluene and chlorobenzene.

The reaction temperature during step iii) is preferably from 0° C. to150° C., more preferably from 50° C. to 150° C., and more preferablyfrom 100° C. to 140° C. Most preferably, the reaction temperature isfrom 110° C. to 125° C.

The reaction time during step iii) is preferably from 10 minutes to 10hours. In case several stages are present, each stage can have areaction time from 10 minutes to 10 hours. The reaction time can bedetermined by a person skilled in the art based on type and the scale ofthe reactor and the catalyst composition.

The mixing speed during the reaction depends on the type of reactor usedand the scale of the reactor used. The mixing speed can be determined bya person skilled in the art and should be sufficient to agitate thereactants.

The obtained reaction product may be washed, usually with an inertaliphatic or aromatic hydrocarbon or halogenated aromatic compound, toobtain the procatalyst for use in an embodiment of the presentinvention. If desired, the reaction and subsequent purification stepsmay be repeated one or more times. A final washing is preferablyperformed with an aliphatic hydrocarbon to result in a suspended or atleast partly dried procatalyst, as described above for the other steps.

Optionally, an activator is present during step iii) of Phase C insteadof an internal donor, this is explained in more detail below in thesection of activators.

The molar ratio of the activator relative to the magnesium may varybetween wide limits, for instance from 0.02 to 0.5. Preferably, thismolar ratio is from 0.05 to 0.4; more preferably from 0.1 to 0.3; andmost preferably from 0.1 to 0.2.

Phase D: Modifying Said Procatalyst with a Metal-Based Modifier.

This phase D is optional in the present invention. In a preferredprocess for modifying the supported procatalyst, this phase comprisesthe following step: Step iv) modifying the third intermediate productwith a metal-modifier to yield a modified intermediate product

After step iv)—if this is carried out—an additional step of contactingthe intermediate product with a catalytic species (in other words, anadditional stage):

Step v) contacting said modified intermediate product with a titaniumhalide and optionally on or more internal donors and/or activators toobtain the present procatalyst. In case no activator is used duringPhase C, an activator is used during step v) of Phase D.

The order of addition, viz. the order of first step iv) and subsequentlystep v) is considered to be important to the formation of the correctclusters of Group 13- or transition metal and titanium forming themodified and more active catalytic center.

Each of these steps is disclosed in more detail below.

It should be noted that the steps iii), iv) and v) (viz. phases C and D)are preferably carried out in the same reactor, viz. in the samereaction mixture, directly following each other.

Preferably, step iv) is carried out directly after step iii) in the samereactor. Preferably, step v) is carried out directly after step iv) inthe same reactor.

Step iv): Group 13- or Transition Metal Modification

The modification with Group 13- or transition metal, preferablyaluminum, ensures the presence of Group 13- or transition metal in theprocatalyst, in addition to magnesium (from the solid support) andtitanium (from the titanation treatment).

Without wishing to be bound by any particular theory, the presentinvention believe that one possible explanation is that the presence ofGroup 13- or transition metal increases the reactivity of the activesite and hence increases the yield of polymer.

Step iv) comprises modifying the third intermediate product obtained instep iii) with a modifier having the formula M(p)X_(p), preferably MX₃,wherein M is a metal selected from the Group 13 metals and transitionmetals of the IUPAC periodic table of elements, p is the oxidation stateof M, and wherein X is a halide to yield a modified intermediateproduct. In case the oxidation state of M, e.g. aluminum, is three, M(p)is Al(III) and there are three monovalent halides X, e.g. AlCl₃ or AlF₃.In case the oxidation state of M, e.g. copper, is two, M(p) is Cu(II)and there are two monovalent halides X, CuBr₂ or CuCl₂.

Step iv) is preferably carried out directly after step iii), morepreferably in the same reactor and preferably in the same reactionmixture. In an embodiment, a mixture of aluminum trichloride and asolvent, e.g. chlorobenzene, is added to the reactor after step iii) hasbeen carried out. After the reaction has completed a solid is allowed tosettle which can either be obtained by decanting or filtration andoptionally purified or a suspension of which in the solvent can be usedfor the following step, viz. step v).

The metal modifier is preferably selected from the group of aluminummodifiers (e.g. aluminum halides), boron modifiers (e.g. boron halides),gallium modifiers (e.g. gallium halides), zinc modifiers (e.g. zinchalides), copper modifiers (e.g. copper halides), thallium modifiers(e.g. thallium halides), indium modifiers (e.g. indium halides),vanadium modifiers (e.g. vanadium halides), chromium modifiers (e.g.chromium halides) and iron modifiers (e.g. iron halides).

Examples of suitable modifiers are aluminum trichloride, aluminumtribromide, aluminum triiodide, aluminum trifluoride, boron trichloride,boron tribromide boron triiodide, boron trifluoride, galliumtrichloride, gallium tribromide, gallium triiodide, gallium trifluoride,zinc dichloride, zinc dibromide, zinc diiodide, zinc difluoride, copperdichloride, copper dibromide, copper diiodide, copper difluoride, copperchloride, copper bromide, copper iodide, copper fluoride, thalliumtrichloride, thallium tribromide, thallium triiodide, thalliumtrifluoride, thallium chloride, thallium bromide, thallium iodide,thallium fluoride, Indium trichloride, indium tribromide, indiumtriiodide, indium trifluoride, vanadium trichloride, vanadiumtribromide, vanadium triiodide, vanadium trifluoride, chromiumtrichloride, chromium dichloride, chromium tribromide, chromiumdibromide, iron dichloride, iron trichloride, iron tribromide, irondichloride, iron triiodide, iron diiodide, iron trifluoride and irondifluoride.

The amount of metal halide added during step iv) may vary according tothe desired amount of metal present in the procatalyst. It may forexample range from 0.1 to 5 wt. % based on the total weight of thesupport, preferably from 0.5 to 1.5 wt. %.

The metal halide is preferably mixed with a solvent prior to theaddition to the reaction mixture. The solvent for this step may beselected from for example aliphatic and aromatic hydrocarbons andhalogenated aromatic solvents with for instance 4-20 carbon atoms.Examples include toluene, xylene, benzene, decane, o-chlorotoluene andchlorobenzene. The solvent may also be a mixture or two or more thereof.

The duration of the modification step may vary from 1 minute to 120minutes, preferably from 40 to 80 minutes, more preferably from 50 to 70minutes. This time is dependent on the concentration of the modifier,the temperature, the type of solvent used etc.

The modification step is preferably carried out at elevated temperatures(e.g. from 50 to 120° C., preferably from 90 to 110° C.).

The modification step may be carried out while stirring. The mixingspeed during the reaction depends i.a. on the type of reactor used andthe scale of the reactor used. The mixing speed can be determined by aperson skilled in the art. As a non-limiting example, mixing may becarried at a stirring speed from 100 to 400 rpm, preferably from 150 to300 rpm, more preferably about 200 rpm.

The wt/vol ratio for the metal halide and the solvent in step iv) is inthe range of weights from 0.01 gram to 0.1 gram over volumes in therange from 5.0 to 100 ml.

The modified intermediate product is present in a solvent. It can bekept in that solvent after which the following step v) is directlycarried out. However, it can also be isolated and/or purified. The solidcan be allowed to settle by stopping the stirring. The supernatant maybe removed by decanting. Otherwise, filtration of the suspension is alsopossible. The solid product may be washed once or several times with thesame solvent used during the reaction or another solvent selected fromthe same group described above. The solid may be re-suspended or may bedried or partially dried for storage.

Subsequent to this step, step v) is carried out to produce theprocatalyst for use in an embodiment of the catalyst system according tothe present invention.

Step v): Titanation of Intermediate Product

This step is very similar to step iii). It relates to the additionaltitanation of the modified intermediate product. It is an additionalstage of contacting with catalytic species (viz. titanation in thisembodiment).

Step v) contacting said modified intermediate product obtained in stepiv) with a halogen-containing titanium compound to obtain theprocatalyst for use in the catalyst system according to an embodiment ofthe present invention. When an activator is used during step iii) aninternal donor is used during this step.

Step v) is preferably carried out directly after step iv), morepreferably in the same reactor and preferably in the same reactionmixture.

In an embodiment, at the end of step iv) or at the beginning of step v)the supernatant is removed from the solid modified intermediate productobtained in step iv) by filtration or by decanting. To the remainingsolid, a mixture of titanium halide (e.g. tetrachloride) and a solvent(e.g. chlorobenzene) may be added. The reaction mixture is subsequentlykept at an elevated temperature (e.g. from 100 to 130° C., such as 115°C.) for a certain period of time (e.g. from 10 to 120 minutes, such asfrom 20 to 60 minutes, e.g. 30 minutes). After this, a solid substanceis allowed to settle by stopping the stirring.

The molar ratio of the transition metal to the magnesium preferably isfrom 10 to 100, most preferably, from 10 to 50.

Optionally, an internal electron donor is also present during this step.Also mixtures of internal electron donors can be used. Examples ofinternal electron donors are disclosed below. The molar ratio of theinternal electron donor relative to the magnesium may vary between widelimits, for instance from 0.02 to 0.75. Preferably, this molar ratio isfrom 0.05 to 0.4; more preferably from 0.1 to 0.4; and most preferablyfrom 0.1 to 0.3.

The solvent for this step may be selected from for example aliphatic andaromatic hydrocarbons and halogenated aromatic solvents with forinstance 4-20 carbon atoms. The solvent may also be a mixture or two ormore thereof.

According to a preferred embodiment of the present invention this stepv) is repeated, in other words, the supernatant is removed as describedabove and a mixture of titanium halide (e.g. tetrachloride) and asolvent (e.g. chlorobenzene) is added. The reaction is continued atelevated temperatures during a certain time which can be same ordifferent from the first time step v) is carried out.

The step may be carried out while stirring. The mixing speed during thereaction depends on the type of reactor used and the scale of thereactor used. The mixing speed can be determined by a person skilled inthe art. This can be the same as discussed above for step iii).

Thus, step v) can be considered to consist of at least two sub steps inthis embodiment, being:

v-a) contacting said modified intermediate product obtained in step iv)with titanium tetrachloride—optionally using an internal donor—to obtaina partially titanated procatalyst; (this can e.g. be considered to bestage II as discussed above for a three-stage Phase C)

v-b) contacting said partially titanated procatalyst obtained in stepv-a) with titanium tetrachloride to obtain the procatalyst. (this cane.g. be considered to be stage III as discussed above for a three-stagePhase C)

Additional sub steps can be present to increase the number of titanationsteps to four or higher (e.g. stages IV, V etc.).

The solid substance (procatalyst) obtained is preferably washed severaltimes with a solvent (e.g. heptane), preferably at elevated temperature,e.g. from 40 to 100° C. depending on the boiling point of the solventused, preferably from 50 to 70° C. After this, the procatalyst,suspended in solvent, is obtained. The solvent can be removed byfiltration or decantation. The procatalyst can be used as such wetted bythe solvent or suspended in solvent or it can be first dried, preferablypartly dried, for storage. Drying can e.g. be carried out by lowpressure nitrogen flow for several hours.

Thus in this embodiment, the total titanation treatment comprises threephases of addition of titanium halide. Wherein the first phase ofaddition is separated from the second and third phases of addition bythe modification with metal halide.

It could be said that the difference between the prior art and thepresent invention is that the titanation step (viz. the step ofcontacting with a titanium halide) according to the present invention issplit into two parts and a Group 13- or transition metal modificationstep is introduced between the two parts or stages of the titanation.Preferably, the first part of the titanation comprises one singletitanation step and the second part of the titanation comprises twosubsequent titanation steps. But different procedures may also be used.When this modification is carried out before the titanation step theincrease in activity was higher as observed by the inventors. When thismodification is carried out after the titanation step the increase inactivity was less as observed by the present inventors.

In short, an embodiment of the present invention comprises the followingsteps in the preparation of a procatalyst suitable for preparation ofthe catalyst system: i) preparation of first intermediate reactionproduct; ii) activation of solid support to yield second intermediatereaction product; iii) first titanation or Stage I to yield thirdintermediate reaction product; iv) modification to yield modifiedintermediate product; v) second titanation or Stage II/III to yield theprocatalyst.

The procatalyst may have a titanium, hafnium, zirconium, chromium orvanadium (preferably titanium) content of from about 0.1 wt. % to about6.0 wt. %, based on the total solids weight, or from about 1.0 wt. % toabout 4.5 wt. %, or from about 1.5 wt. % to about 3.5 wt. %.

The weight ratio of titanium, hafnium, zirconium, chromium or vanadium(preferably titanium) to magnesium in the solid procatalyst may be fromabout 1:3 to about 1:60, or from about 1:4 to about 1:50, or from about1:6 to 1:30. Weight percent is based on the total weight of theprocatalyst.

The transition metal-containing solid procatalyst for use in a catalystsystem according to the present invention comprises a transition metalhalide (e.g. titanium halide, chromium halide, hafnium halide, zirconiumhalide or vanadium halide) supported on a metal or metalloid compound(e.g. a magnesium compound or a silica compound).

Preferably, a magnesium-based or magnesium-containing support is used inthe present invention. Such a support is prepared frommagnesium-containing support-precursors, such as magnesium halides,magnesium alkyls and magnesium aryls, and also magnesium alkoxy andmagnesium aryloxy compounds.

The support may be activated using activation compounds as described inmore detail under Phase B.

The catalyst may further be activated during Phase C as discussed forthe process. This activation increases the yield of the resultingcatalyst composition in olefin polymerization.

Several activators can be used, such as benzamide, alkylbenzoates, andmonoesters. Each of these will be discussed below.

A benzamide activator has a structure according to Formula X:

R⁷⁰ and R⁷¹ are each independently selected from hydrogen or an alkyl.Preferably, said alkyl has between 1 and 6 carbon atoms, more preferablybetween 1-3 carbon atoms. More preferably, R⁷⁰ and R⁷¹ are eachindependently selected from hydrogen or methyl.

R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are each independently selected from hydrogen, aheteroatom (preferably a halide), or a hydrocarbyl group, e.g. selectedfrom alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 10carbon atoms, more preferably between 1-8 carbon atoms, even morepreferably between 1 and 6 carbon atoms.

Suitable non-limiting examples of “benzamides” include benzamide (R⁷⁰and R⁷¹ are both hydrogen and each of R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ arehydrogen) also denoted as BA-2H or methylbenzamide (R⁷⁰ is hydrogen; R⁷¹is methyl and each of R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are hydrogen) also denotedas BA-HMe or dimethylbenzamide (R⁷⁰ and R⁷¹ are methyl and each of R⁷²,R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are hydrogen) also denoted as BA-2Me. Other examplesinclude monoethylbenzamide, diethylbenzamide, methylethylbenzamide,2-(trifluormethyl)benzamide, N,N-dimethyl-2-(trifluormethyl)benzamide,3-(trifluormethyl)benzamide, N,N-dimethyl-3-(trifluormethyl)benzamide,2,4-dihydroxy-N-(2-hydroxyethyl)benzamide,N-(1H-benzotriazol-1-ylmethyl)benzamide, 1-(4-ethylbenzoyl)piperazine,1-benzoylpiperidine.

It has surprisingly been found by the present inventors that when thebenzamide activator is added during the first stage of the processtogether with the catalytic species or directly after the addition ofthe catalytic species (e.g. within 5 minutes) an even higher increase inthe yield is observed compared to when the activator is added duringstage II or stage III of the process.

It has surprisingly been found by the present inventors that thebenzamide activator having two alkyl groups (e.g. dimethylbenzamide ordiethylbenzamide, preferably dimethylbenzamide) provides an even higherincrease in the yield than either benzamide or monoalkyl benzamide.

Without wishing to be bound by a particular theory the present inventorsbelieve that the fact that the most effective activation is obtainedwhen the benzamide activator is added during stage I has the followingreason. It is believed that the benzamide activator will bind thecatalytic species and is later on substituted by the internal donor whenthe internal donor is added.

Alkylbenzoates may be used as activators. The activator may hence beselected from the group consisting of alkylbenzoates having an alkylgroup having between 1 and 10, preferably between 1 and 6 carbon atoms.Examples of suitable alkyl benzoates are methylbenzoate, ethylbenzoateaccording to Formula II, n-propylbenzoate, iso-propylbenzoate,n-butylbenzoate, 2-butylbenzoate, t-butylbenzoate.

More preferably, the activator is ethylbenzoate. In a even morepreferred embodiment, ethylbenzoate as activator is added during stepiii) and a benzamide internal donor is added during step v), mostpreferably 4-[benzoyl(methyl)amino]pentan-2-yl benzoate according toFormula XII:

Monoesters may be used as activators. The monoester according to thepresent invention can be any ester of a monocarboxylic acid known in theart. The structures according to Formula V are also monoesters but arenot explained in this section, see the section on Formula V. Themonoester can have the formula XXIII

R⁹⁴—CO—OR⁹⁵  Formula XXIII

R⁹⁴ and R⁹⁵ are each independently selected from a hydrocarbyl groupe.g. selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl oralkylaryl groups, and one or more combinations thereof. R⁹⁴ may moreoverbe hydrogen. Said hydrocarbyl group may be linear, branched or cyclic.Said hydrocarbyl group may be substituted or unsubstituted. Saidhydrocarbyl group may contain one or more heteroatoms. Preferably, saidhydrocarbyl group has between 1 and 10 carbon atoms, more preferablybetween 1-8 carbon atoms, even more preferably between 1 and 6 carbonatoms. When R⁹⁴ is an aryl, this structure is similar to Formula V.Examples of aromatic monoesters are discussed with reference to formulaV.

Preferably said monoester is an aliphatic monoester. Suitable examplesof monoesters include formates, for instance, butyl formate; acetates,for instance ethyl acetate, amyl acetate and butyl acetate; acrylates,for instance ethyl acrylate, methyl methacrylate and isobutylmethacrylate. More preferably, the aliphatic monoester is an acetate.Most preferably, the aliphatic monoester is ethyl acetate.

In an embodiment, the monoester used in step iii) is an ester of analiphatic monocarboxylic acid having between 1 and 10 carbon atoms.Wherein R⁹⁴ is an aliphatic hydrocarbyl group.

The molar ratio between the monoester in step iii) and Mg may range from0.05 to 0.5, preferably from 0.1 to 0.4, and most preferably from 0.15to 0.25.

The monoester is not used as a stereospecificity agent, like usualinternal donors are known to be in the prior art. The monoester is usedas an activator.

Without to be bound by any theory, the inventors believe that themonoester used in the process according to the present inventionparticipates at the formation of the magnesium halogen (e.g. MgCl₂)crystallites during the interaction of Mg-containing support withtitanium halogen (e.g. TiCl₄). The monoester may form intermediatecomplexes with Ti and Mg halogen compounds (for instance, TiCl₄,TiCl₃(OR), MgCl₂, MgCl(OEt), etc.) and help with the removal of titaniumproducts from solid particles to mother liquor and affect the activityof final catalyst. Therefore, the monoester according to the presentinvention can also be referred to as an activator.

As used herein, an “internal electron donor” or an “internal donor” is acompound added during formation of the procatalyst that donates a pairof electrons to one or more metals present in the resultant procatalyst.Not bounded by any particular theory, it is believed that the internalelectron donor assists in regulating the formation of active sitesthereby enhancing catalyst stereoselectivity.

The internal electron donor can be any compound known in the art to beused as internal electron donor. Suitable examples of internal donorsinclude aromatic acid esters, such as monocarboxylic acid ester ordicarboxylic acid esters (e.g. ortho-dicarboxylic acid esters such asphthalic acid esters), (N-alkyl)amidobenzoates, 1,3-diethers, silylesters, fluorenes, succinates and/or combinations thereof.

It is preferred to use so-called phthalate free internal donors becauseof increasingly stricter government regulations about the maximumphthalate content of polymers. This leads to an increased demand inphthalate free catalyst compositions.

An aromatic acid ester can be used as internal donor. As used herein, an“aromatic acid ester” is a monocarboxylic acid ester (also called“benzoic acid ester”) as shown in Formula V or a dicarboxylic acid ester(e.g. an o-dicarboxylic acid also called “phthalic acid ester”) as shownin Formula VI:

R³⁰ is selected from a hydrocarbyl group independently selected e.g.from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 10 carbonatoms, more preferably from 1 to 8 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms. Suitable examples of hydrocarbyl groupsinclude alkyl-, cycloalkyl-, alkenyl-, alkadienyl-, cycloalkenyl-,cycloalkadienyl-, aryl-, aralkyl, alkylaryl, and alkynyl-groups.

R³¹, R³², R³³, R³⁴, R³⁵ are each independently selected from hydrogen, aheteroatom (preferably a halide), or a hydrocarbyl group, e.g. selectedfrom alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 10 carbonatoms, more preferably from 1 to 8 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms.

Suitable non-limiting examples of “benzoic acid esters” include an alkylp-alkoxybenzoate (such as ethyl p-methoxybenzoate, methylp-ethoxybenzoate, ethyl p-ethoxybenzoate), an alkyl benzoate (such asethyl benzoate, methyl benzoate), an alkyl p-halobenzoate (ethylp-chlorobenzoate, ethyl p-bromobenzoate), and benzoic anhydride. Thebenzoic acid ester is preferably selected from ethyl benzoate, benzoylchloride, ethyl p-bromobenzoate, n-propyl benzoate and benzoicanhydride. The benzoic acid ester is more preferably ethyl benzoate.

Wherein R⁴⁰ and R⁴¹ are each independently a hydrocarbyl group e.g.selected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylarylgroups, and one or more combinations thereof. Said hydrocarbyl group maybe linear, branched or cyclic. Said hydrocarbyl group may be substitutedor unsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 10 carbonatoms, more preferably from 1 to 8 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms. Suitable examples of hydrocarbyl groupsinclude alkyl-, cycloalkyl-, alkenyl-, alkadienyl-, cycloalkenyl-,cycloalkadienyl-, aryl-, aralkyl, alkylaryl, and alkynyl-groups.

R⁴², R⁴³, R⁴⁴, R⁴⁵ are each independently selected from hydrogen, ahalide or a hydrocarbyl group, e.g. selected from alkyl, alkenyl, aryl,aralkyl, alkoxycarbonyl or alkylaryl groups, and one or morecombinations thereof. Said hydrocarbyl group may be linear, branched orcyclic. Said hydrocarbyl group may be substituted or unsubstituted. Saidhydrocarbyl group may contain one or more heteroatoms. Preferably, saidhydrocarbyl group has from 1 to 10 carbon atoms, more preferably from 1to 8 carbon atoms, even more preferably from 1 to 6 carbon atoms.

Suitable non-limiting examples of phthalic acid esters include dimethylphthalate, diethyl phthalate, di-n-propyl phthalate, diisopropylphthalate, di-n-butyl phthalate, diisobutyl phthalate, di-t-butylphthalate, diisoamyl phthalate, di-tert-amyl phthalate, dineopentylphthalate, di-2-ethylhexyl phthalate, di-2-ethyldecyl phthalate,bis(2,2,2-trifluoroethyl) phthalate, diisobutyl 4-t-butylphthalate, anddiisobutyl 4-chlorophthalate. The phthalic acid ester is preferablydi-n-butyl phthalate or diisobutyl phthalate.

As used herein a “di-ether” may be a 1,3-di(hydrocarboxy)propanecompound, optionally substituted on the 2-position represented by theFormula VII,

R⁵¹ and R⁵² are each independently selected from a hydrogen or ahydrocarbyl group e.g. selected from alkyl, alkenyl, aryl, aralkyl,alkoxycarbonyl or alkylaryl groups, and one or more combinationsthereof. Said hydrocarbyl group may be linear, branched or cyclic. Saidhydrocarbyl group may be substituted or unsubstituted. Said hydrocarbylgroup may contain one or more heteroatoms. Preferably, said hydrocarbylgroup has from 1 to 10 carbon atoms, more preferably from 1 to 8 carbonatoms, even more preferably from 1 to 6 carbon atoms. Suitable examplesof hydrocarbyl groups include alkyl-, cycloalkyl-, alkenyl-,alkadienyl-, cycloalkenyl-, cycloalkadienyl-, aryl-, aralkyl, alkylaryl,and alkynyl-groups.

R⁵³ and R⁵⁴ are each independently selected from a hydrocarbyl group,e.g. selected from alkyl, alkenyl, aryl, aralkyl, or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 10 carbonatoms, more preferably from 1 to 8 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms.

Suitable examples of dialkyl diether compounds include1,3-dimethoxypropane, 1,3-diethoxypropane, 1,3-dibutoxypropane,1-methoxy-3-ethoxypropane, 1-methoxy-3-butoxypropane,1-methoxy-3-cyclohexoxypropane, 2,2-dimethyl-1,3-dimethoxypropane,2,2-diethyl-1,3-dimethoxypropane, 2,2-di-n-butyl-1,3-dimethoxypropane,2,2-diiso-butyl-1,3-dimethoxypropane,2-ethyl-2-n-butyl-1,3-dimethoxypropane,2-n-propyl-2-cyclopentyl-1,3-dimethoxypropane,2,2-dimethyl-1,3-diethoxypropane,2-n-propyl-2-cyclohexyl-1,3-diethoxypropane,2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane,2-n-butyl-1,3-dimethoxypropane, 2-sec-butyl-1,3-dimethoxypropane,2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-diethoxypropane,2-cumyl-1,3-diethoxypropane, 2-(2-phenyllethyl)-1,3-dimethoxypropane,2-(2-cyclohexylethyl)-1,3-dimethoxypropane,2-(p-chlorophenyl)-1,3-dimethoxypropane,2-(diphenylmethyl)-1,3-dimethoxypropane,2-(1-naphthyl)-1,3-dimethoxypropane,2-(fluorophenyl)-1,3-dimethoxypropane,2-(1-decahydronaphthyl)-1,3-dimethoxypropane,2-(p-t-butylphenyl)-1,3-dimethoxypropane,2,2-dicyclohexyl-1,3-dimethoxypropane,2,2-di-npropyl-1,3-dimethoxypropane,2-methyl-2-n-propyl-1,3-dimethoxypropane,2-methyl-2-benzyl-1,3-dimethoxypropane,2-methyl-2-ethyl-1,3-dimethoxypropane,2-methyl-2-phenyl-1,3-dimethoxypropane,2-methyl-2-cyclohexyl-1,3-dimethoxypropane,2,2-bis(p-chlorophenyl)-1,3-dimethoxypropane,2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane,2-methyl-2-isobutyl-1,3-dimethoxypropane,2-methyl-2-(2-ethylhexyl)-1,3-dimethoxy propane,2-methyl-2-isopropyl-1,3-dimethoxypropane,2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane,2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane,2,2-diisobutyl-1,3-diethoxypropane,2,2-diisobutyl-1,3-di-n-butoxypropane,2-isobutyl-2-isopropyl-1,3-dimethoxypropane,2,2-di-sec-butyl-1,3-dimethoxypropane,2,2-di-t-butyl-1,3-dimethoxypropane,2,2-dineopentyl-1,3-dimethoxypropane,2-isopropyl-2-isopentyl-1,3-dimethoxypropane,2-phenyl-2-benzyl-1,3-dimethoxypropane,2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane,2-isopropyl-2-(3,7-dimethyloctyl) 1,3-dimethoxypropane,2,2-diisopropyl-1,3-dimethoxypropane,2-isopropyl-2-cyclohexylmethyl-1,3-dimethoxypropane,2,2-diisopentyl-1,3-dimethoxypropane,2-isopropyl-2-cyclohexyl-1,3-dimethoxypropane,2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane,2,2-dicylopentyl-1,3-dimethoxypropane,2-n-heptyl-2-n-pentyl-1,3-dimethoxypropane,9,9-bis(methoxymethyl)fluorene,1,3-dicyclohexyl-2,2-bis(methoxymethyl)propane,3,3-bis(methoxymethyl)-2,5-dimethylhexane, or any combination of theforegoing. In an embodiment, the internal electron donor is1,3-dicyclohexyl-2,2-bis(methoxymethyl)propane,3,3-bis(methoxymethyl)-2,5-dimethylhexane,2,2-dicyclopentyl-1,3-dimethoxypropane and combinations thereof.

Examples of preferred ethers are diethers, such as2-ethyl-2-butyl-1,3-dimethoxypropane,2-isopropyl-2-isopentyl-1,3-dimethoxypropane and 9,9-bis (methoxymethyl)fluorene:

As used herein a “succinate acid ester” is a 1,2-dicarboxyethane and canbe used as internal donor of Formula VIII:

R⁶⁰ and R⁶¹ are each independently a hydrocarbyl group, e.g. selectedfrom alkyl, alkenyl, aryl, aralkyl, or alkylaryl groups, and one or morecombinations thereof. Said hydrocarbyl group may be linear, branched orcyclic. Said hydrocarbyl group may be substituted or unsubstituted. Saidhydrocarbyl group may contain one or more heteroatoms. Preferably, saidhydrocarbyl group has from 1 to 10 carbon atoms, more preferably from 1to 8 carbon atoms, even more preferably from 1 to 6 carbon atoms.

R⁶², R⁶³, R⁶⁴, and R⁶⁵ are each independently selected from hydrogen ora hydrocarbyl group, e.g. selected from alkyl, alkenyl, aryl, aralkyl,alkoxycarbonyl or alkylaryl groups, and one or more combinationsthereof. Said hydrocarbyl group may be linear, branched or cyclic. Saidhydrocarbyl group may be substituted or unsubstituted. Said hydrocarbylgroup may contain one or more heteroatoms. Preferably, said hydrocarbylgroup has from 1 to 20 carbon atoms.

More preferably, R⁶², R⁶³, R⁶⁴, and R⁶⁵ are independently selected froma group consisting of hydrogen, C₁-C₁₀ straight and branched alkyl;C₃-C₁₀ cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀ alkaryl and aralkyl group.

Even more preferably, R⁶², R⁶³, R⁶⁴, and R⁶⁵ are independently selectedfrom a group consisting of hydrogen, methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, iso-butyl, t-butyl, phenyltrifluoromethyl and halophenyl group. Most preferably, one of R⁶² andR⁶³ is selected from methyl, ethyl, n-propyl, iso-propyl, n-butyl,sec-butyl, iso-butyl, t-butyl, whereas the other is a hydrogen atom; andone of R⁶⁴ and R⁶⁵ is selected from methyl, ethyl, n-propyl, iso-propyl,n-butyl, sec-butyl, iso-butyl, t-butyl, whereas the other is a hydrogenatom.

Suitable examples of succinate acid ester include diethyl2,3-di-isopropylsuccinate, diethyl 2,3-di-n-propylsuccinate, diethyl2,3-di-isobutylsuccinate, diethyl 2,3-di-sec-butylsuccinate, dimethyl2,3-di-isopropylsuccinate, dimethyl 2,3-di-n-propylsuccinate, dimethyl2,3-di-isobutylsuccinate and dimethyl 2,3-di-sec-butylsuccinate.

Examples of other organic compounds containing a heteroatom arethiophenol, 2-methylthiophene, isopropyl mercaptan, diethylthioether,diphenylthio-ether, tetrahydrofuran, dioxane, anisole, acetone,triphenylphosphine, triphenylphosphite, diethylphosphate anddiphenylphosphate.

The silyl ester as internal donor can be any silyl ester or silyl diolester known in the art, for instance as disclosed in US 2010/0130709.

When an aminobenzoate (AB) according to Formula XI is used as aninternal donor this ensures a better control of stereochemistry andallows preparation of polyolefins having a broader molecular weightdistribution.

Aminobenzoates suitable as internal donor according to the presentinvention are the compounds represented by Formula XI:

Wherein R⁸⁰ is an aromatic group, selected from aryl or alkylaryl groupsand may be substituted or unsubstituted. Said aromatic group may containone or more heteroatoms. Preferably, said aromatic group has from 6 to20 carbon atoms. It should be noted that the two R⁸⁰ groups may be thesame but may also be different.

R⁸⁰ can be the same or different than any of R⁸¹-R⁸⁷ and is preferablyan aromatic substituted and unsubstituted hydrocarbyl having 6 to 10carbon atoms.

More preferably, R⁸⁰ is selected from the group consisting of C₆-C₁₀aryl unsubstituted or substituted with e.g. an acylhalide or analkoxyde; and C₇-C₁₀ alkaryl and aralkyl group; for instance,4-methoxyphenyl, 4-chlorophenyl, 4-methylphenyl.

Particularly preferred, R⁸⁰ is substituted or unsubstituted phenyl,benzyl, naphthyl, ortho-tolyl, para-tolyl oranisol group. Mostpreferably, R⁸⁰ is phenyl.

R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are each independently selected fromhydrogen or a hydrocarbyl group, e.g. selected from alkyl, alkenyl,aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one or morecombinations thereof. Said hydrocarbyl group may be linear, branched orcyclic. Said hydrocarbyl group may be substituted or unsubstituted. Saidhydrocarbyl group may contain one or more heteroatoms. Preferably, saidhydrocarbyl group has from 1 to 20 carbon atoms.

More preferably, R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are independentlyselected from a group consisting of hydrogen, C₁-C₁₀ straight andbranched alkyl; C₃-C₁₀ cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀ alkaryl andaralkyl group.

Even more preferably, R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are independentlyselected from a group consisting of hydrogen, methyl, ethyl, propyl,isopropyl, butyl, t-butyl, phenyl, trifluoromethyl and halophenyl group.

Most preferably, R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are each hydrogen,methyl, ethyl, propyl, t-butyl, phenyl or trifluoromethyl. Preferably,R⁸¹ and R⁸² is each a hydrogen atom.

More preferably, R⁸¹ and R⁸² is each a hydrogen atom and each of R⁸³,R⁸⁴, R⁸⁵, and R⁸⁶ is selected from the group consisting of hydrogen,C₁-C₁₀ straight and branched alkyls; C₃-C₁₀ cycloalkyls; C₆-C₁₀ aryls;and C₇-C₁₀ alkaryl and aralkyl group.

Preferably, at least one of R⁸³ and R⁸⁴ and at least one of R⁸⁵ and R⁸⁶is a hydrocarbyl group.

More preferably, when at least one of R⁸³ and R⁸⁴ and one of R⁸⁵ and R⁸⁶is a hydrocarbyl group having at least one carbon atom then the otherone of R⁸³ and R⁸⁴ and of R⁸⁵ and R⁸⁶ is each a hydrogen atom.

Most preferably, when one of R⁸³ and R⁸⁴ and one of R⁸⁵ and R⁸⁶ is ahydrocarbyl group having at least one carbon atom, then the other one ofR⁸³ and R⁸⁴ and of R⁸⁵ and R⁸⁶ is each a hydrogen atom and R⁸¹ and R⁸²is each a hydrogen atom.

Preferably, R⁸¹ and R⁸² is each a hydrogen atom and one of R⁸³ and R⁸⁴and one of R⁸⁵ and R⁸⁶ is selected from the group consisting of C₁-C₁₀straight and branched alkyl; C₃-C₁₀ cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀alkaryl and aralkyl group.

More preferably, R⁸⁵ and R⁸⁶ is selected from the group consisting ofC₁-C₁₀ alkyl, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl,phenyl, trifluoromethyl and halophenyl group; and most preferably, oneof R⁸³ and R⁸⁴, and one of R⁸⁵ and R⁸⁶ is methyl.

R⁸⁷ is a hydrogen or a hydrocarbyl group, e.g. selected from alkyl,alkenyl, aryl, aralkyl, or alkylaryl groups, and one or morecombinations thereof. Said hydrocarbyl group may be linear, branched orcyclic. Said hydrocarbyl group may be substituted or unsubstituted. Saidhydrocarbyl group may contain one or more heteroatoms. Preferably, saidhydrocarbyl group has from 1 to 20 carbon atoms, more preferably from 1to 10 carbon atoms. R⁸⁷ may be the same or different than any of R⁸¹,R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ with the provision that R⁸⁷ is not ahydrogen atom.

More preferably, R⁸⁷ is selected from a group consisting of C₁-C₁₀straight and branched alkyl; C₃-C₁₀cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀alkaryl and aralkyl group.

Even more preferably, R⁸⁷ is selected from a group consisting of methyl,ethyl, propyl, isopropyl, butyl, t-butyl, phenyl, benzyl and substitutedbenzyl and halophenyl group.

Most preferably, R⁸⁷ is methyl, ethyl, propyl, isopropyl, benzyl orphenyl; and even most preferably, R⁸⁷ is methyl, ethyl or propyl.

Without being limited thereto, particular examples of the compounds offormula (XI) are the structures as depicted in formulas (XII)-(XXII).For instance, the structure in Formula (XII) may correspond to4-[benzoyl(methyl)amino]pentan-2-yl benzoate; Formula (XIII) to3-[benzoyl(cyclohexyl)amino]-1-phenylbutyl benzoate; Formula (XIV) to3-[benzoyl(propan-2-yl)amino]-1-phenylbutyl benzoate; Formula (XV) to4-[benzoyl(propan-2-yl)amino]pentan-2-yl benzoate; Formula (XVI) to4-[benzoyl(methyl)amino]-1,1,1-trifluoropentan-2-yl benzoate; Formula(XVII) to 3-(methylamino)-1,3-diphenylpropan-1-oldibenzoate; Formula(XVIII) to 2,2,6,6-tetramethyl-5-(methylamino)heptan-3-ol dibenzoate;Formula (XIX) to 4-[benzoyl (ethyl)amino]pentan-2-yl benzoate; Formula(XX) to 3-(methyl)amino-propan-1-ol dibenzoate; Formula (XXI) to3-(methyl)amino-2,2-dimethylpropan-1-ol dibenzoate; Formula (XXII) to4-(methylamino)pentan-2-yl bis (4-methoxy)benzoate).

It has been surprisingly found out that the catalyst compositioncomprising the compound of formula (XI) as an internal electron donorshows better control of stereochemistry and allows preparation ofpolyolefins, particularly of polypropylenes having broader molecularweight distribution and higher isotacticity.

In an embodiment, the catalyst system according to the inventioncomprises the compound having formula (XI) as the only internal electrondonor in a Ziegler-Natta catalyst composition.

The compounds of formula (XII), (XIX), (XXII) and (XVIII) are the mostpreferred internal electron donors in the catalyst system according tothe present invention as they allow preparation of polyolefins havingbroader molecular weight distribution and higher isotacticity.

The compound according to formula (XI) can be made by any method knownin the art. In this respect, reference is made to J. Chem. Soc. Perkintrans. 11994, 537-543 and to Org. Synth. 1967, 47, 44. These documentsdisclose a step a) of contacting a substituted 2,4-diketone with asubstituted amine in the presence of a solvent to give aβ-enaminoketone; followed by a step b) of contacting the β-enaminoketonewith a reducing agent in the presence of a solvent to give aγ-aminoalcohol. The substituted 2,4-diketone and the substituted aminecan be applied in step a) in amounts ranging from 0.5 to 2.0 mole,preferably from 1.0 to 1.2 mole. The solvent in steps a) and b) may beadded in an amount of 5 to 15 volume, based on the total amount of thediketone, preferably of 3 to 6 volume. The beta-enaminoketone todiketone mole ratio in step b) may be of from 0.5 to 6, preferably from1 to 3. The reducing agent to beta-enaminoketone mole ratio in step b)may be of from 3 to 8, preferably from 4 to 6; the reducing agent may beselected from the group comprising metallic sodium, NaBH₄ in aceticacid, Ni—Al alloy. Preferably, the reducing agent is metallic sodiumbecause it is a cheap reagent.

The γ-aminoalcohol that can be used for making compound (XI) can besynthesized as described in the literature and also mentioned herein orthis compound can be directly purchased commercially and used as astarting compound in a reaction to obtain the compound represented byformula (XI). Particularly, the γ-aminoalcohol can be reacted with asubstituted or unsubstituted benzoyl chloride in the presence of a baseto obtain the compound represented by formula (XI)(referred herein alsoas step c), regardless that γ-aminoalcohol was synthesized as describedin the literature or commercially purchased). The molar ratio betweenthe substituted or unsubstituted benzoyl chloride and the γ-aminoalcoholmay range from 2 to 4, preferably from 2 to 3. The base may be any basicchemical compound that is able to deprotonate the γ-aminoalcohol. Saidbase can have a pK_(a) of at least 5; or at least 10 or preferably from5 to 40, wherein pK_(a) is a constant already known to the skilledperson as the negative logarithm of the acid dissociation constantk_(a). Preferably, the base is pyridine; a trialkyl amine, e.g.triethylamine; or a metal hydroxide e.g. NaOH, KOH. Preferably, the baseis pyridine. The molar ratio between the base and the gamma-aminoalcoholmay range from 3 to 10, preferably from 4 to 6.

The solvent used in any of steps a), b) and c) can be selected from anyorganic solvents, such as toluene, dichloromethane, 2-propanol,cyclohexane or mixtures of any organic solvents. Preferably, toluene isused in each of steps a), b) and c). More preferably, a mixture oftoluene and 2-propanol is used in step b). The solvent in step c) can beadded in an amount of 3 to 15 volume, preferably from 5 to 10 volumebased on the γ-aminoalcohol.

The reaction mixture in any of steps a), b) and c) may be stirred byusing any type of conventional agitators for more than about 1 hour,preferably for more than about 3 hours and most preferably for more thanabout 10 hours, but less than about 24 hours. The reaction temperaturein any of steps a) and b) may be the room temperature, i.e. of fromabout 15 to about 30° C., preferably of from about 20 to about 25° C.The reaction temperature in step c) may range from 0 to 10° C.,preferably from 5 to 10° C. The reaction mixture in any of steps a), b)and c) may be refluxed for more than about 10 hours, preferably for morethan about 20 hours but less than about 40 hours or until the reactionis complete (reaction completion may be measured by Gas Chromatography,GC). The reaction mixture of steps a) and b) may be then allowed to coolto room temperature, i.e. at a temperature of from about 15 to about 30°C., preferably of from about 20 to about 25° C. The solvent and anyexcess of components may be removed in any of steps a), b) and c) by anymethod known in the art, such as evaporation or washing. The obtainedproduct in any of steps b) and c) can be separated from the reactionmixture by any method known in the art, such as by extraction over metalsalts, e.g. sodium sulfate.

The molar ratio of the internal donor of formula (XI) relative to themagnesium can be from 0.02 to 0.5. Preferably, this molar ratio is from0.05 to 0.2.

A benzamide can be used as internal donor. Suitable compounds have astructure according to formula X:

R⁷⁰ and R⁷¹ are each independently selected from hydrogen or an alkyl.Preferably, said alkyl has from 1 to 6 carbon atoms, more preferablyfrom 1 to 3 carbon atoms. More preferably, R⁷⁰ and R⁷¹ are eachindependently selected from hydrogen or methyl.

R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are each independently selected from hydrogen, aheteroatom (preferably a halide), or a hydrocarbyl group, e.g. selectedfrom alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has from 1 to 10 carbonatoms, more preferably from 1 to 8 carbon atoms, even more preferablyfrom 1 to 6 carbon atoms.

Suitable non-limiting examples of “benzamides” include benzamide (R⁷⁰and R⁷¹ are both hydrogen and each of R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ arehydrogen) also denoted as BA-2H or methylbenzamide (R⁷⁰ is hydrogen; R⁷¹is methyl and each of R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are hydrogen) also denotedas BA-HMe or dimethylbenzamide (R⁷⁰ and R⁷¹ are methyl and each of R⁷²,R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are hydrogen) also denoted as BA-2Me. Other examplesinclude monoethylbenzamide, diethylbenzamide, methylethylbenzamide,2-(trifluormethyl)benzamide, N,N-dimethyl-2-(trifluormethyl)benzamide,3-(trifluormethyl)benzamide, N,N-dimethyl-3-(trifluormethyl)benzamide,2,4-dihydroxy-N-(2-hydroxyethyl)benzamide,N-(1H-benzotriazol-1-ylmethyl)benzamide, 1-(4-ethylbenzoyl)piperazine,1-benzoylpiperidine.

As discussed in WO 2013124063 1,5-diesters according to Formula XXV canbe used as internal donors. These 1,5-diesters have two chiral centerson their C2 and C4 carbon atoms. Four isomers exist, being the 2R, 4Smeso isomer, the 2S, 4R meso isomers and the 2S, 4S and 2R, 4R isomers.A mixture of all of them is called “rac” diester.

R¹⁵ is independently a hydrocarbyl group independently selected e.g.from alkyl, alkenyl, aryl, aralkyl, or alkylaryl groups, and one or morecombinations thereof. Said hydrocarbyl group may be linear, branched orcyclic. Said hydrocarbyl group may be substituted or unsubstituted. Saidhydrocarbyl group may contain one or more heteroatoms. Preferably, saidhydrocarbyl group has from 1 to 20 carbon atoms.

R¹⁶ and R¹⁷ are different with respect to each other. Both R¹⁶ groupsmay be the same or different. Both R¹⁷ groups may be the same ordifferent. The R¹⁶ and R¹⁷ groups and independently selected from thegroup consisting of hydrogen, halogen, and hydrocarbyl groupindependently selected e.g. from alkyl, alkenyl, aryl, aralkyl,alkoxycarbonyl or alkylaryl groups, and one or more combinationsthereof. Said hydrocarbyl group may be linear, branched or cyclic. Saidhydrocarbyl group may be substituted or unsubstituted. Said hydrocarbylgroup may contain one or more heteroatoms. Preferably, said hydrocarbylgroup has from 1 to 20 carbon atoms.

An example of a compound according to formula XXV is pentanedioldibenzoate.

The compound according to Formula XXV has two stereocenters (at C2 andC4), comprises two so-called stereocenters each giving rise to twodifferent configurations and thus to a total of four stereoisomers.There are two sets of diastereomers (or diastereoisomers), eachcomprising two enantiomers. Enantiomers differ in both stereocenters andare therefore mirror images of one another.

The R¹⁶ and the R¹⁷ groups may be switched in position. In other words,the mirror image of the compound of Formula XXV having the two R¹⁷groups on the left hand of the structure. The compound in formula XXV isthe (2R, 4S) meso-isomer whereas the mirror image (not shown) is the(2S, 4R) meso-isomer. The compound of Formula XXV is a meso-isomer, i.e.it contains two stereocenters (chiral centers) but it is not chiral.

The following two other isomers are possible: a (2S, 4S)-isomer (notshown), a (2R, 4R)-isomer (not shown). R and S illustrate the chiralcenters of the molecules, as known to the skilled person. When a mixtureof 2S, 4S and 2R, 4R is present, this is called “rac”. These internaldonors are disclosed in detail in WO 2013/124063 which shows Fisherprojections of all isomers.

In an embodiment, at least one group of R¹⁶ and R¹⁷ may be selected fromthe group consisting of hydrogen, halogen, C1-C10 linear or branchedalkyl, C3-C10 cycloalkyl, C6-C10 aryl, and C7-C10 alkaryl or aralkylgroup. More preferably, at least one group of R¹⁶ and R¹⁷ is selectedfrom the group consisting of hydrogen, methyl, ethyl, propyl, isopropyl,butyl, t-butyl, phenyl, and halophenyl group.

Preferably, either R¹⁶ and R¹⁷ represents hydrogen. More preferably, R¹⁶and R¹⁷ represent a methyl or an ethyl group. Particularly preferred iswhen either of R¹⁶ and R¹⁷ represents hydrogen and the other R¹⁶ and R¹⁷represents a methyl or an ethyl group.

R¹⁵ is preferably independently selected from benzene-ring containinggroups, such as phenyl, phenyl substituted by alkyl, alkoxy or halogen;optionally the carbon atom(s) on the benzene ring being replaced by ahetero-atom of oxygen atom and/or nitrogen atom; alkenyl or phenylsubstituted alkenyl, such as vinyl, propenyl, styryl; alkyl, such asmethyl, ethyl, propyl, etc.

More preferably, R¹⁵ represents a phenyl group. Particularly preferredis meso pentane-2,4-diol dibenzoate (mPDDB).

The catalyst system according to the present invention includes aco-catalyst. As used herein, a “co-catalyst” is a term well-known in theart in the field of Ziegler-Natta catalysts and is recognized to be asubstance capable of converting the procatalyst to an activepolymerization catalyst. Generally, the co-catalyst is an organometalliccompound containing a metal from group 1, 2, 12 or 13 of the PeriodicSystem of the Elements (Handbook of Chemistry and Physics, 70th Edition,CRC Press, 1989-1990).

The co-catalyst may include any compounds known in the art to be used as“co-catalysts”, such as hydrides, alkyls, or aryls of aluminum, lithium,zinc, tin, cadmium, beryllium, magnesium, and combinations thereof. Theco-catalyst may be a hydrocarbyl aluminum co-catalyst represented by theformula R²⁰ ₃Al.

R²⁰ is independently selected from a hydrogen or a hydrocarbyl group,selected e.g. from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl oralkylaryl groups, and one or more combinations thereof. Said hydrocarbylgroup may be linear, branched or cyclic. Said hydrocarbyl group may besubstituted or unsubstituted. Said hydrocarbyl group may contain one ormore heteroatoms. Preferably, said hydrocarbyl group has between 1 and20 carbon atoms, more preferably between 1-12 carbon atoms, even morepreferably between 1 and 6 carbon atoms. On the proviso that at leastone R²⁰ is a hydrocarbyl group. Optionally, two or three R²⁰ groups arejoined in a cyclic radical forming a heterocyclic structure.

Non-limiting examples of suitable R²⁰ groups are: methyl, ethyl, propyl,isopropyl, butyl, isobutyl, t-butyl, pentyl, neopentyl, hexyl,2-methylpentyl, heptyl, octyl, isooctyl, 2-ethylhexyl,5,5-dimethylhexyl, nonyl, decyl, isodecyl, undecyl, dodecyl, phenyl,phenethyl, methoxyphenyl, benzyl, tolyl, xylyl, naphthyl, methylnapthyl,cyclohexyl, cycloheptyl, and cyclooctyl.

Suitable examples of the hydrocarbyl aluminum compounds as co-catalystinclude triisobutylaluminum, trihexylaluminum, di-isobutylaluminumhydride, dihexylaluminum hydride, isobutylaluminum dihydride,hexylaluminum dihydride, diisobutylhexylaluminum, isobutyldihexylaluminum, trimethylaluminum, triethylaluminum, tripropylaluminum,triisopropylaluminum, tri-n-butylaluminum, trioctylaluminum,tridecylaluminum, tridodecylaluminum, tribenzylaluminum,triphenylaluminum, trinaphthylaluminum, and tritolylaluminum. In anembodiment, the cocatalyst is selected from triethylaluminum,triisobutylaluminum, trihexylaluminum, di-isobutylaluminum hydride anddihexylaluminum hydride. More preferably, trimethylaluminum,triethylaluminum, triisobutylaluminum, and/or trioctylaluminum. Mostpreferably, triethylaluminum (abbreviated as TEAL).

The co-catalyst can also be a hydrocarbyl aluminum compound representedby the formula R²¹ _(m)AlX²¹ _(3-m).¹

R²¹ is an alkyl group. Said alkyl group may be linear, branched orcyclic. Said alkyl group may be substituted or unsubstituted.Preferably, said alkyl group has between 1 and 20 carbon atoms, morepreferably between 1-12 carbon atoms, even more preferably between 1 and6 carbon atoms.

Non-limiting examples of suitable R²¹ groups are: methyl, ethyl, propyl,isopropyl, butyl, isobutyl, t-butyl, pentyl, neopentyl, hexyl,2-methylpentyl, heptyl, octyl, isooctyl, 2-ethylhexyl,5,5-dimethylhexyl, nonyl, decyl, isodecyl, undecyl, and dodecyl.

X²¹ is selected from the group of consisting of fluoride (F—), chloride(Cl—), bromide (Br—) or iodide (I—) or an alkoxide (RO⁻). The value form is preferably 1 or 2.

Non-limiting examples of suitable alkyl aluminum halide compounds forco-catalyst include tetraethyl-dialuminoxane, methylaluminoxane,isobutylaluminoxane, tetraisobutyl-dialuminoxane,diethyl-aluminumethoxide, diisobutylaluminum chloride, methylaluminumdichloride, diethylaluminum chloride, ethylaluminum dichloride anddimethylaluminum chloride.

Non-limiting examples of suitable compounds includetetraethyldialuminoxane, methylaluminoxane, isobutylaluminoxane,tetraisobutyldialuminoxane, diethylaluminum ethoxide, diisobutylaluminumchloride, methylaluminum dichloride, diethylaluminum chloride,ethylaluminum dichloride and dimethylaluminum chloride.

Preferably, the co-catalyst is triethylaluminum. The molar ratio ofaluminum to titanium may be from about 5:1 to about 500:1 or from about10:1 to about 200:1 or from about 15:1 to about 150:1 or from about 20:1to about 100:1. The molar ratio of aluminum to titanium is preferablyabout 45:1.

More details about the preferred embodiment of the present externaldonor are provided below.

Thus, the external electron donor according to the present invention(according to Formula I′) may have any one of the following formulas:

Si(L)₄(n=4,m=0)

Si(L)₃(R¹²)₁(n=3,m=1)

Si(L)₃(OR¹¹)₁(n=3,m=0)

Si(L)₂(R¹²)₂(n=2,m=2)

Si(L)₂(OR¹¹)₁(R¹²)₁(n=2,m=1)

Si(L)₂(OR¹¹)₂(n=2,m=0)

Si(L)₁(R¹²)₃(n=1,m=3)

Si(L)₁(OR¹¹)₁(R¹²)₂(n=1,m=2)

Si(L)₁(OR¹¹)₂(R¹²)₁(n=1,m=1)

Si(L)₁(OR¹¹)₃(n=1,m=0)

The compound according to the present invention (according to FormulaIa′) may have any one of the following formulas:

Si(L)₃(OR¹¹)₁(q=3,m=0)

Si(L)₂(OR¹¹)₁(R¹²)₁(q=2,m=1)

Si(L)₂(OR¹¹)₂(q=2,m=0)

Si(L)₁(OR¹¹)₁(R¹²)₂(q=1,m=2)

on the proviso that when X=Y=phenyl, R¹² groups may not be both a methylif R¹¹ is butyl.

Si(L)₁(OR¹¹)₂(R¹²)₁(q=1,m=1)

on the proviso that when R¹² and R¹¹ are both methyl X may not be phenylwhen Y is —CH₂—Si(CH₃)₃ and on the proviso that when R¹² is —(CH₂)₃—NH₂and R¹¹ is ethyl, X may not be —NH—C═NH(NH₂)— when Y is—NH—(CH₂)₃—Si(OCH₂CH₃)₃

Si(L)₁(OR¹¹)₃(q=1,m=0)

Preferably, in the compound according to Formula Ia′ when n is 3, than mis 0. Preferably, when n is 2, than m is 0 or 1. Preferably, when n is1, m is 0.

Particularly, in the compounds according to formula I′ or Ia′ the Lgroup has a single substituent on the nitrogen atom, this singlesubstituent being a carbon atom which is doubly bonded to the nitrogenatom, which is also defined as the “imine carbon atom”.

According to the invention, X and Y can also be each independentlyselected from a group comprising a heteroatom selected from 13, 14, 15,16 or 17 groups of the IUPAC Periodic Table of the Elements, throughwhich X and Y are each independently bonded to the imine carbon atom ofFormula II, wherein the heteroatom is substituted with a groupconsisting of a linear, branched and cyclic alkyl having at most 20carbon atoms, optionally containing a heteroatom selected from group 13,14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements; and/orwith an aromatic substituted and unsubstituted hydrocarbyl having 6 to20 carbon atoms, optionally containing a heteroatom selected from group13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements.

Preferably, substituents X and Y are bonded to the imine carbon atomthrough a group 14, 15 or 16 atom according to the IUPAC Periodic Tableof the Elements. More preferably, substituents X and Y are groups bondedto the imine carbon atom through carbon, silicon, nitrogen, phosphorous,oxygen or sulfur. Substituents X and Y are preferably independentlyselected from a group consisting of a hydrogen atom, alkyl, aryl, andsilyl, amide, imide, alkoxy, aryloxy, thioalkoxy, sulfide, phosphide andphosphinimide group of up to 20, for instance 1 to 10 carbon atoms.

More preferably, both substituents X and Y in the L group comprise anitrogen atom through which X and Y are each bonded to the imine carbonatom. In such case, L is referred herein as a “guanidine” group.

In the context of the present invention a guanidine ligand is when bothX and Y are according to b) and more specifically a group comprising anitrogen heteroatom, through which X and Y are each independently bondedto the imine carbon atom of Formula II, and wherein the heteroatom ofboth X and Y is substituted with two groups, selected from a hydrogenand a group consisting of a linear, branched and cyclic alkyl having atmost 20 carbon atoms, optionally containing a heteroatom selected fromgroup 13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements;and/or with an aromatic substituted and unsubstituted hydrocarbyl having6 to 20 carbon atoms, optionally containing a heteroatom selected fromgroup 13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements.In other words, the imine carbon atom is bonded to two nitrogen atoms.

According to the invention, X and Y may be each independently selectedfrom a group consisting of a linear, branched and cyclic alkyl having atmost 20 carbon atoms, optionally containing a heteroatom selected fromgroup 13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements;and an aromatic substituted and unsubstituted hydrocarbyl having 6 to 20carbon atoms, optionally containing a heteroatom selected from group 13,14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements.

Preferably, L group comprises a substituent X comprising a carbon atomby which X is bonded to the imine carbon atom and a substituent Ycomprising a carbon atom by which Y is bonded to the imine carbon atom.In such case, L is referred herein as a “ketimide” group.

In the context of the present invention a ketimide ligand is when both Xand Y are according to c) or d) viz. an alkyl or aryl group. In otherwords, the imine carbon atom is bonded to two carbon atoms.

More preferably, L group comprises a substituent X comprising a carbonatom, by which X is bonded to the imine carbon atom and Y comprises anitrogen atom, through which Y is bonded to the imine carbon atom. Insuch case, L is referred herein as an “amidine” group.

In the context of the present invention an amidine ligand is when eitherX or Y is according to b) and more specifically a group comprising anitrogen heteroatom, through which X or Y IS bonded to the imine carbonatom of Formula II, and wherein the heteroatom of said X or Y issubstituted with two groups, selected from a hydrogen and a groupconsisting of a linear, branched and cyclic alkyl having at most 20carbon atoms, optionally containing a heteroatom selected from group 13,14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements; and/orwith an aromatic substituted and unsubstituted hydrocarbyl having 6 to20 carbon atoms, optionally containing a heteroatom selected from group13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements. Theother of X and Y is according to c) or d) viz. an alkyl or aryl group.In other words, the imine carbon atom is bonded to one carbon atom andone nitrogen atom.

The substituents X and Y may also be linked to each other by a spacergroup, which results in X and Y together with the imine carbon atombeing part of a ring system. The spacer group may be any hydrocarbongroup having 1 to 20 carbon atoms, such as —(CH₂)_(n)—, with n being 1to 20, preferably 1 to 10 carbon atoms and more preferably 1 to 6 carbonatoms. Most preferably, the spacer is an ethylene or propylene group,such as —(CH₂)_(n)— with n being 2 or 3.

In a first specific example, the external donor according to formula I′may have a structure corresponding to Formula I′ wherein n=1, m=2,X=Y=phenyl, both R¹² groups are methyl, and R¹¹ is butyl.

In a second specific example, the external donor according to formula I′may have a structure corresponding to Formula I′ wherein n=4, m=0,X=methyl, and Y=ethyl.

In a third specific example, the external donor according to formula I′may have a structure corresponding to Formula I′ wherein n=1, m=1,X=phenyl, Y=—CH₂—Si(CH₃)₃, and R¹²=R¹¹=methyl.

In a fourth specific example, the external donor according to formula I′may have a structure corresponding to Formula I′ wherein n=1, m=1,X=—NH—C═NH(NH₂)—, Y=—NH—(CH₂)₃—Si(OCH₂CH₃)₃, and R¹²=—(CH₂)₃—NH₂;R¹¹=ethyl.

The present invention also relates to a compound having the structureaccording to Formula Ia′:

Si(L)_(q)(OR¹¹)_(4-q-m)(R¹²)_(m)  Formula Ia′

wherein,Si is a silicon atom with valency 4+;O is an oxygen atom with valency 2− and O is bonded to Si via asilicon-oxygen bond;q is 1, 2 or 3;m is 0, 1 or 2on the proviso that when q=3, m=0on the proviso that when q=2, m=0 or 1on the proviso than when q=1, m=2each R¹¹ group is independently selected from the group consisting oflinear, branched and cyclic alkyl having at most 20 carbon atoms andaromatic substituted and unsubstituted hydrocarbyl having 6 to 20 carbonatoms;each R¹² group is independently selected from the group consisting oflinear, branched and cyclic alkyl having at most 20 carbon atoms andaromatic substituted and unsubstituted hydrocarbyl having 6 to 20 carbonatoms;each L group is independently a group represented by the followingstructure

wherein,L is bonded to the silicon atom via a nitrogen-silicon bond;L has a single substituent on the nitrogen atom, where this singlesubstituent is an imine carbon atom; andX and Y are each independently selected from the group consisting of:

-   a) a hydrogen atom;-   b) a group comprising a heteroatom selected from group 13, 14, 15,    16 or 17 of the IUPAC Periodic Table of the Elements, through which    X and Y are each independently bonded to the imine carbon atom of    Formula II, wherein the heteroatom is substituted with a group    consisting of a linear, branched and cyclic alkyl having at most 20    carbon atoms, optionally containing a heteroatom selected from group    13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements;    and/or with an aromatic substituted and unsubstituted hydrocarbyl    having 6 to 20 carbon atoms, optionally containing a heteroatom    selected from group 13, 14, 15, 16 or 17 of the IUPAC Periodic Table    of the Elements;-   c) a linear, branched and cyclic alkyl having at most 20 carbon    atoms, optionally containing a heteroatom selected from group 13,    14, 15, 16 or 17 of the IUPAC Periodic Table of the Elements; and-   d) an aromatic substituted and unsubstituted hydrocarbyl having 6 to    20 carbon atoms, optionally containing a heteroatom selected from    group 13, 14, 15, 16 or 17 of the IUPAC Periodic Table of the    Elements.    L and R¹¹ of Formula Ia′ are the same as L and R¹¹ as defined herein    for Formula I′.

The silane compounds according to Formula I′ and Ia′ can be synthesizedby any methods known in the art, e.g. by reacting a metal salt of groupL, such as of a ketimine, amidine or guanidine withSi(OR¹¹)_(4-m)(R¹²)_(m) or (Z_(n)Si(OR¹¹)_(4-n n-m)(R¹²)_(m)) atdifferent molar ratios, i.e. molar ratio of (metal salts of groupL)/(Si(OR¹¹)_(4-m)(R¹²)_(m)) of 1, 2, 3, 4 or excess of metal salt ofgroup L, preferably in a hydrocarbon dispersant or solvent, such ashexane, heptane, pentane, ethers at temperatures between −100° C. and80° C. The metal salt of group L may be synthesized in situ or isolatedby deprotonating a neutral L of Formula II, such as ketimine, amidine orguanidine in a solvent, preferably a hydrocarbon solvent, such ashexane, heptane, pentane, preferably at reaction temperature between−100° C. and 80° C. The deprotonating agent may be chosen from any ofthe list, which is known by the person skilled in the art. Non-limitingdeprotonating agents are lithium diethylamide, n-butyl lithium, t-butyllithium, methyl magnesium bromide, methyl magnesium chloride, methylmagnesium iodide, ethyl magnesium bromide, sodium hydride, lithiumhydride, potassium carbonate and sodium carbonate.

For example, the metal salt of the ketimide can be synthesized bysynthetic procedures, which are known from the prior art, e.g. adi-t-butyl ketimide lithium compound can be synthesized according to apublished procedure, D. Armstrong, D. Barr, R. Sanith, J. Chem. Soc.Dalton Trans. 1987, 1071. The metal salt of an amidine can besynthesized by synthetic procedures, which are known from theliterature, e.g. by reacting an amide anion with a benzonitrile compound(U.S. Pat. No. 7,956,140B2) or the pinner reaction (EP2493906) followedby a deprotonation using a hydrocarbyl lithium or hydrocarbyl magnesiumhalide compound. The metal salt of a guanidine can be synthesized bysynthetic procedures which are known from the literature, e.g. the1,1,3,3-tetramethyl guanidine anion can be synthesized according toEP10214708 or Journal of the American Chemical Society, 93:7, Apr. 7,1971, 1502, J. C. S. Dalton (doi:10.1039/DT9720001501).

The metal salt of group L may remain in solution or precipitate from thesolvent in which the reaction is performed. In case the metal salt ofgroup L precipitates during the deprotonation reaction, the remainingsolid metal salt of group L can be isolated by filtration and purifiedby multiple washings with additional solvent. In case the metal salt ofgroup L remains in solution, the solution can be used further as such.

Compounds of the invention of Formula I′ or Ia′ may also be synthesizedby reacting an alkoxy silane halide represented by Formula XXIVb, viz.Z_(n)Si(OR¹¹)_(4-n-m)(OR¹²)_(m) with a metal salt of group L, such as aketimine, amidine or guanidine preferably in a hydrocarbon dispersant orsolvent, such as hexane, heptane, pentane, ethers at temperaturesbetween −100° C. and 80° C. The molar ratios of (metal salt of groupL)/(Z_(n)Si(OR¹¹)_(4-n-m)(OR¹²)_(m)) in this reaction preferably equaln.

Alternatively, compounds of the invention of Formula I′ or Ia′ may alsobe synthesized by reacting a neutral L group, such as a ketimine,amidine or guanidine with an alkoxy silane halide of Formula XXIVb inthe presence or in the absence of a base. Non-limiting examples of suchbases used are triethyl amine, diethyl amine, DBU andtetraazacyclononane (Mironov, V. F. et al., Doklady Akademii Nauk. SSSR,1971, 199(1), 103-106).

The molar ratio that can be applied in the reaction of the neutral groupL equals that of n in Formula XXIVb and the base can be use equimolar tothat or, preferably, in excess. The reaction is preferably performed ina hydrocarbon dispersant or solvent, such as alkanes, aromatic solventsor ethereal solvents at temperatures between 25° C. and 150° C.Non-limiting examples of solvents used are hexane, heptane, toluene,p-xylene, diethylether and tetrahydrofuran. In the alkoxy silane haliderepresented by Formula XXIVb, Z is halogen group, and more preferably achlorine group; n=1, 2 or 3.

In the protonated L group represented by Formula L⁺ X and Y are definedthe same as for the L group of Formula I″.

In the protonated L group represented by L⁺, X and Y are defined thesame as for the L group.

Neutral compounds L can be synthesized through methods known in the art,e.g. Caron, Stephane et al., Journal of Organic Chemistry, 2010, 75(3),945-947; Buchwald, S. L. et al., J. Org. Chem. 2008, 73, 7102;Zuideveld, M. A. et al. U.S. Pat. No. 7,956,140B2; Kretschmer, W. P. etal., Chem. Commun., 2002, 608 and WO02/070569; Zuideveld, M. A. et al.EP2319874; J. McMeeking et al. U.S. Pat. No. 6,114,481.

In some cases, the compound L can be obtained as its hydrogen halidesalt. Specific examples of halogen halides are hydrogen chloride,hydrogen bromide and hydrogen iodide. The neutral compound L-H can beobtained by reacting the hydrogen halide salt of L with a base.

In order to show the structural variety possible for L groups,non-exhaustive examples of L are represented by the followingstructures:

In an embodiment, the external electron donor according to the presentinvention consists of only the compound of Formula I′ or Ia′. In anembodiment, the external electron donor comprises the compound ofFormula I′ or Ia′ and one or more additional compounds.

The additional compound(s) in the external donor according to theinvention may be one or more alkoxysilanes. The alkoxysilane compoundcan have any of the structures disclosed herein. The alkoxysilane isdescribed by Formula IX

SiR_(r)(OR′)_(4-r)  Formula IX

where R independently is hydrogen or a hydrocarbyl or an amino groupoptionally substituted with one or more substituents containing one ormore Group 14, 15, 16, or 17 heteroatoms of the IUPAC Periodic Table ofthe Elements, said R containing up to 20 atoms, apart from hydrogen andhalogen; R′ is a C1-20 alkyl group; and r is 0, 1, 2 or 3. In anembodiment, R is C6-12 aryl, alkyl or aralkyl, C3-12 cycloalkyl, C3-12branched alkyl, or C3-12 cyclic or acyclic amino group, R′ is C1-4alkyl, and r is 1 or 2. Suitable examples of such silane compositionsinclude dicyclopentyldimethoxysilane, di-t-butyldimethoxysilane,ethylcyclohexyldimethoxysilane, methylcyclohexyldiethoxysilane,diphenyldimethoxysilane, diiso butyl dimethoxysilane, diisopropyldimethoxysilane, diisobutyldiethoxysilane,ethylcyclohexyldimethoxysilane, di-n-propyldimethoxysilane,di-n-butyldimethoxysilane, cyclopentyltrimethoxysilane,isopropyltrimethoxysilane, n-propyltrimethoxysilane,n-propyltriethoxysilane, ethyltriethoxysilane, tetramethoxysilane,tetraethoxysilane, diethylaminotriethoxysilane,cyclopentylpyrrolidinodimethoxysilane, bis(pyrrolidino) dimethoxysilane,bis(perhydroisoquinolino)dimethoxysilane, and dimethyldimethoxysilane.

In an embodiment, the alkoxysilane is dicyclopentyldimethoxysilane,cyclohexylmethyldimethoxysilane (C-donor), n-propyltrimethoxysilane(nPTMS) and any combination thereof. Preferably, the additional externaldonor is dicyclopentyldimethoxysilane.

The external donor of the present invention may include from about 0.1mol. % to about 99.9 mol. % of the silane represented by Formula I′ andfrom about 99.9 mol. % to about 0.1 mol. % of the additionalalkoxysilane.

The Si/Ti molar ratio in the catalyst system can range from 0.1 to 40,preferably from 0.1 to 20, even more preferably from 1 to 20 and mostpreferably from 2 to 10.

The catalyst system according to the present invention comprising thespecial silicon-based external electron donor as defined herein exhibitsat least one of the following properties: improved activity, improvedhydrogen response, improved ethylene response and reduced lump formationduring polymerization. The catalyst system according to the presentinvention comprising the special external electron donor as definedherein allows producing olefin-based polymers with high isotacticity,high melt flow rate and high ethylene content in case the polyolefin isa propylene-ethylene copolymer.

The invention also relates to a process to make the catalyst system bycontacting a Ziegler-Natta type procatalyst, a co-catalyst and anexternal electron donor. The procatalyst, the co-catalyst and theexternal donor can be contacted in any way known to the skilled personin the art; and as also described herein, more specifically as in theExamples.

The invention further relates to a process for making a polyolefin bycontacting an olefin with the catalyst system according to the presentinvention. The procatalyst, the co-catalyst, the external donor and theolefin can be contacted in any way known to the skilled person in theart; and as also described herein.

For instance, the external donor in the catalyst system according to thepresent invention can be complexed with the co-catalyst and mixed withthe procatalyst (pre-mix) prior to contact between the catalystcomposition and the olefin. The external donor can also be addedindependently to the polymerization reactor. The procatalyst, theco-catalyst, and the external donor can be mixed or otherwise combinedprior to addition to the polymerization reactor.

Contacting the olefin with the catalyst system according to the presentinvention can be done under standard polymerization conditions, known tothe skilled person in the art. See for example Pasquini, N. (ed.)“Polypropylene handbook” 2^(nd) edition, Carl Hanser Verlag Munich,2005. Chapter 6.2 and references cited therein which is incorporated byreference.

The polymerization process may be a gas phase, a slurry or a bulkpolymerization process, operating in one or more than one reactor. Oneor more olefin monomers can be introduced in a polymerization reactor toreact with the catalyst composition and to form an olefin-based polymer(or a fluidized bed of polymer particles).

In the case of polymerization in a slurry (liquid phase), a dispersingagent is present. Suitable dispersing agents include for examplepropane, n-butane, isobutane, n-pentane, isopentane, hexane (e.g. iso-or n-), heptane (e.g. iso- or n-), octane, cyclohexane, benzene,toluene, xylene, liquid propylene and/or mixtures thereof. Thepolymerization such as for example the polymerization temperature andtime, monomer pressure, avoidance of contamination of catalyst, choiceof polymerization medium in slurry processes, the use of furtheringredients (like hydrogen) to control polymer molar mass, and otherconditions are well known to persons of skill in the art. Thepolymerization temperature may vary within wide limits and is, forexample for propylene polymerization, from 0° C. to 120° C., preferablyfrom 40° C. to 100° C. The pressure during (propylene)(co)polymerization is for instance from 0.1 to 6 MPa, preferably from 1to 4 MPa.

Several types of polyolefins are prepared such as homopolyolefins,random copolymers and heterophasic polyolefin. For heterophasicpolypropylene, the following is observed.

Heterophasic propylene copolymers are generally prepared in one or morereactors, by polymerization of propylene and optionally one or moreother olefins, for example ethylene, in the presence of a catalyst andsubsequent polymerization of a propylene-α-olefin mixture. The resultingpolymeric materials can show multiple phases (depending on monomerratio), but the specific morphology usually depends on the preparationmethod and monomer ratio. The heterophasic propylene copolymers employedin the process according to present invention can be produced using anyconventional technique known to the skilled person, for examplemultistage process polymerization, such as bulk polymerization, gasphase polymerization, slurry polymerization, solution polymerization orany combinations thereof. Any conventional catalyst systems, forexample, Ziegler-Natta or metallocene may be used. Such techniques andcatalysts are described, for example, in WO06/010414; Polypropylene andother Polyolefins, by Ser van der Ven, Studies in Polymer Science 7,Elsevier 1990; WO06/010414, U.S. Pat. No. 4,399,054 and U.S. Pat. No.4,472,524.

The molar mass of the polyolefin obtained during the polymerization canbe controlled by adding hydrogen or any other agent known to be suitablefor the purpose during the polymerization. The polymerization can becarried out in a continuous mode or batch-wise. Slurry-, bulk-, andgas-phase polymerization processes, multistage processes of each ofthese types of polymerization processes, or combinations of thedifferent types of polymerization processes in a multistage process arecontemplated herein. Preferably, the polymerization process is a singlestage gas phase process or a multistage, for instance a two-stage gasphase process, e.g. wherein in each stage a gas-phase process is used orincluding a separate (small) pre-polymerization reactor.

Examples of gas-phase polymerization processes include both stirred bedreactors and fluidized bed reactor systems; such processes are wellknown in the art. Typical gas phase olefin polymerization reactorsystems typically comprise a reactor vessel to which an olefinmonomer(s) and a catalyst system can be added and which contain anagitated bed of growing polymer particles. Preferably the polymerizationprocess is a single stage gas phase process or a multistage, forinstance a 2-stage, gas phase process wherein in each stage a gas-phaseprocess is used.

As used herein, “gas phase polymerization” is the way of an ascendingfluidizing medium, the fluidizing medium containing one or moremonomers, in the presence of a catalyst through a fluidized bed ofpolymer particles maintained in a fluidized state by the fluidizingmedium optionally assisted by mechanical agitation. Examples of gasphase polymerization are fluid bed, horizontal stirred bed and verticalstirred bed.

“fluid-bed,” “fluidized,” or “fluidizing” is a gas-solid contactingprocess in which a bed of finely divided polymer particles is elevatedand agitated by a rising stream of gas optionally assisted by mechanicalstirring. In a “stirred bed” upwards gas velocity is lower than thefluidization threshold.

A typical gas-phase polymerization reactor (or gas phase reactor)include a vessel (i.e., the reactor), the fluidized bed, a productdischarge system and may include a mechanical stirrer, a distributionplate, inlet and outlet piping, a compressor, a cycle gas cooler or heatexchanger. The vessel may include a reaction zone and may include avelocity reduction zone, which is located above the reaction zone (viz.bed). The fluidizing medium may include propylene gas and at least oneother gas such as an olefin and/or a carrier gas such as hydrogen ornitrogen. The contacting can occur by way of feeding the catalystcomposition into the polymerization reactor and introducing the olefininto the polymerization reactor. In an embodiment, the process includescontacting the olefin with a co-catalyst. The co-catalyst can be mixedwith the procatalyst (pre-mix) prior to the introduction of theprocatalyst into the polymerization reactor. The co-catalyst may be alsoadded to the polymerization reactor independently of the procatalyst.The independent introduction of the co-catalyst into the polymerizationreactor can occur (substantially) simultaneously with the procatalystfeed.

The olefin according to the invention may be selected from mono- anddi-olefins containing from 2 to 40 carbon atoms. Suitable olefinmonomers include alpha-olefins, such as ethylene, propylene,alpha-olefins having from 4 to 20 carbon atoms (viz. C4-20), such as1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene,1-decene, 1-dodecene and the like; C4-C20 diolefins, such as1,3-butadiene, 1,3-pentadiene, norbornadiene, 5-vinyl-2-norbornene(VNB), 1,4-hexadiene, 5-ethylidene-2-norbornene (ENB) anddicyclopentadiene; vinyl aromatic compounds having from 8 to 40 carbonatoms (viz. C8-C40) including styrene, o-, m- and p-methylstyrene,divinylbenzene, vinylbiphenyl, vinylnapthalene; and halogen-substitutedC8-C40 vinyl aromatic compounds such as chlorostyrene and fluorostyrene.

Preferably, the olefin is propylene or a mixture of propylene andethylene, to result in a propylene-based polymer, such as propylenehomopolymer or propylene-olefin copolymer. The olefin may an a-olefinhaving up to 10 carbon atoms, such as ethylene, butane, hexane, heptane,octene. A propylene copolymer is herein meant to include both so-calledrandom copolymers which typically have relatively low comonomer content,e.g. up to 10 mol. %, as well as so-called impact PP copolymers orheterophasic PP copolymers comprising higher comonomer contents, e.g.from 5 to 80 mol. %, more typically from 10 to 60 mol. %. The impact PPcopolymers are actually blends of different propylene polymers; suchcopolymers can be made in one or two reactors and can be blends of afirst component of low comonomer content and high crystallinity, and asecond component of high comonomer content having low crystallinity oreven rubbery properties. Such random and impact copolymers arewell-known to the skilled in the art. A propylene-ethylene randomcopolymer may be produced in one reactor. Impact PP copolymers may beproduced in two reactors: polypropylene homopolymer may be produced in afirst reactor; the content of the first reactor is subsequentlytransferred to a second reactor into which ethylene (and optionallypropylene) is introduced. This results in production of apropylene-ethylene copolymer (i.e. an impact copolymer) in the secondreactor.

The present invention also relates to a polyolefin, preferably apolypropylene obtained or obtainable by a process, comprising contactingan olefin, preferably propylene or a mixture of propylene and ethylenewith the catalyst system according to the present invention. The termspolypropylene and propylene-based polymer are used hereininterchangeable. The polypropylene may be a propylene homopolymer or amixture of propylene and ethylene, such as a propylene-based copolymer,e.g. heterophasic propylene-olefin copolymer; random propylene-olefincopolymer, preferably the olefin in the propylene-based copolymers beinga C2, or C4-C6 olefin, such as ethylene, butylene, pentene or hexene.Such propylene-based (co)polymers are known to the skilled person in theart; they are also described herein.

The present invention also relates to a polyolefin, preferably apropylene-based polymer obtained or obtainable by a process as describedherein, comprising contacting propylene or a mixture of propylene andethylene with a catalyst system according to the present invention.

In one embodiment according to the present invention a (random)copolymer of propylene and ethylene monomers is obtained. For such apolymer, properties such as XS and reduced haze increase after time maybe important.

The content of the comonomer used in addition to propylene (e.g.ethylene or C4-C6-olefin) may vary from 0 to 8 wt. % based on the totalweight of the polymer, preferably from 1 to 4 wt. %.

“comonomer content” or “C2 content” as used in the present descriptionmeans the weight percentage (wt. %) of respectively comonomer orethylene incorporated incorporated into the total polymer weightobtained and measured with FT-IR. The FT-IR method was calibrated usingNMR data.

Several polymer properties are discussed here.

Xylene soluble fraction (XS) is preferably from about 0.5 wt. % to about10 wt. %, or from about 1 wt. % to about 8 wt. %, or from 2 to 6 wt. %,or from about 1 wt. % to about 5 wt. %. Preferably, the xylene amount(XS) is lower than 6 wt. %, preferably lower than 5 wt. %, morepreferably lower than 4 wt. % or even lower than 3 wt. % and mostpreferably lower than 2.7 wt. %.

The lump content is preferably below 10 wt. %, preferably below 4 wt. %and more preferably below 3 wt. %.

The production rate is preferably from about 1 kg/g/hr to about 100kg/g/hr, or from about 10 kg/g/hr to about 40 kg/g/hr.

MFR is preferably from about 0.01 g/10 min to about 2000 g/10 min, orfrom about 0.01 g/10 min to about 1000 g/10 min; or from about 0.1 g/10min to about 500 g/10 min, or from about 0.5 g/10 min to about 150 g/10min, or from about 1 g/10 min to about 100 g/10 min.

The olefin polymer obtained in the present invention is considered to bea thermoplastic polymer. The thermoplastic polymer composition accordingto the invention may also contain one or more of usual additives, likethose mentioned above, including stabilizers, e.g. heat stabilizers,anti-oxidants, UV stabilizers; colorants, like pigments and dyes;clarifiers; surface tension modifiers; lubricants; flame-retardants;mold-release agents; flow improving agents; plasticizers; anti-staticagents; impact modifiers; blowing agents; fillers and reinforcingagents; and/or components that enhance interfacial bonding betweenpolymer and filler, such as a maleated polypropylene, in case thethermoplastic polymer is a polypropylene composition. The skilled personcan readily select any suitable combination of additives and additiveamounts without undue experimentation.

The amount of additives depends on their type and function; typically isof from 0 to about 30 wt. %; preferably of from 0 to about 20 wt. %;more preferably of from 0 to about 10 wt. % and most preferably of from0 to about 5 wt. % based on the total composition. The sum of allcomponents added in a process to form the polyolefins, preferably thepropylene-base polymers or compositions thereof should add up to 100 wt.%.

The thermoplastic polymer composition of the invention may be obtainedby mixing one or more of the thermoplastic polymers with one or moreadditives by using any suitable means. Preferably, the thermoplasticpolymer composition of the invention is made in a form that allows easyprocessing into a shaped article in a subsequent step, like in pellet orgranular form. The composition can be a mixture of different particlesor pellets; like a blend of a thermoplastic polymer and a master batchof nucleating agent composition, or a blend of pellets of athermoplastic polymer comprising one of the two nucleating agents and aparticulate comprising the other nucleating agent, possibly pellets of athermoplastic polymer comprising said other nucleating agent.Preferably, the thermoplastic polymer composition of the invention is inpellet or granular form as obtained by mixing all components in anapparatus like an extruder; the advantage being a composition withhomogeneous and well-defined concentrations of the nucleating agents(and other components).

The invention also relates to the use of the polyolefins, preferably thepropylene-based polymers (also called polypropylenes) according to theinvention in injection molding, blow molding, extrusion molding,compression molding, casting, thin-walled injection molding, etc. forexample in food contact applications.

Furthermore, the invention relates to a shaped article comprising thepolyolefin, preferably the propylene-based polymer according to thepresent invention.

The polyolefin, preferably the propylene-based polymer according to thepresent invention may be transformed into shaped (semi)-finishedarticles using a variety of processing techniques. Examples of suitableprocessing techniques include injection molding, injection compressionmolding, thin wall injection molding, extrusion, and extrusioncompression molding. Injection molding is widely used to producearticles such as for example caps and closures, batteries, pails,containers, automotive exterior parts like bumpers, automotive interiorparts like instrument panels, or automotive parts under the bonnet.Extrusion is for example widely used to produce articles, such as rods,sheets, films and pipes. Thin wall injection molding may for example beused to make thin wall packaging applications both for food and non-foodsegments. This includes pails and containers and yellow fats/margarinetubs and dairy cups.

It is noted that the invention relates to all possible combinations offeatures recited in the claims. Features described in the descriptionmay further be combined.

Although the invention has been described in detail for purposes ofillustration, it is understood that such detail is solely for thatpurpose and variations can be made therein by those skilled in the artwithout departing from the spirit and scope of the invention as definedin the claims.

It is further noted that the invention relates to all possiblecombinations of features described herein, preferred in particular arethose combinations of features that are present in the claims.

It is further noted that the term ‘comprising’ does not exclude thepresence of other elements. However, it is also to be understood that adescription on a product comprising certain components also discloses aproduct consisting of these components. Similarly, it is also to beunderstood that a description on a process comprising certain steps alsodiscloses a process consisting of these steps.

1. A catalyst system for olefin polymerization comprising aZiegler-Natta type procatalyst, a co-catalyst and an external electrondonor, wherein the external electron donor comprises a compound havingthe structure according to Formula I′:Si(L)_(n)(OR¹¹)_(4-n-m)(R¹²)_(m)  Formula I′ wherein, Si is a siliconatom with valency 4+; O is an oxygen atom with valency 2− and O isbonded to Si via a silicon-oxygen bond; n is 1, 2, 3 or 4; m is 0, 1, 2or 3; n+m≦4; each R¹¹ group is independently selected from the groupconsisting of linear, branched and cyclic alkyl having at most 20 carbonatoms and aromatic substituted and unsubstituted hydrocarbyl having 6 to20 carbon atoms; each R¹¹ group is independently selected from the groupconsisting of linear, branched and cyclic alkyl having at most 20 carbonatoms and aromatic substituted and unsubstituted hydrocarbyl having 6 to20 carbon atoms; and each L group is independently a group representedby the following structure

wherein, L is bonded to the silicon atom via a nitrogen-silicon bond; Lhas a single substituent on the nitrogen atom, where this singlesubstituent is an imine carbon atom; and X and Y are each independentlyselected from the group consisting of: a) a hydrogen atom; b) a groupcomprising a heteroatom selected from Group 13, 14, 15, 16 or 17 of theIUPAC Periodic Table of the Elements through which X and Y are eachindependently bonded to the imine carbon atom of Formula II, wherein theheteroatom is substituted with a group consisting of a linear, branchedand cyclic alkyl groups having at most 20 carbon atoms, optionallycomprising a heteroatom selected from Group 13, 14, 15, 16 or 17 of theIUPAC Periodic Table of the Elements; and/or with an aromaticsubstituted and unsubstituted hydrocarbyl group having 6 to 20 carbonatoms, optionally comprising a heteroatom selected from Group 13, 14,15, 16 or 17 of the IUPAC Periodic Table of the Elements; c) a linear,branched and cyclic alkyl having at most 20 carbon atoms, optionallycomprising a heteroatom selected from Group 13, 14, 15, 16 or 17 of theIUPAC Periodic Table of the Elements; and d) an aromatic substituted andunsubstituted hydrocarbyl having 6 to 20 carbon atoms, optionallycomprising a heteroatom selected from Group 13, 14, 15, 16 or 17 of theIUPAC Periodic Table of the Elements.
 2. The catalyst system accordingto claim 1, wherein in L at least one of X and Y is selected from b), c)or d).
 3. The catalyst system according to claim 1, wherein L isguanidine, amidine or ketimide.
 4. The catalyst system according toclaim 1, wherein R¹¹ is an alkyl having at most 10 carbon atoms.
 5. Aprocess for preparing the catalyst system according to claim 1,comprising contacting a Ziegler-Natta type procatalyst, a co-catalystand an external electron donor comprising the compound according toFormula I′.
 6. The process according to claim 5, said processcomprising: A) providing a Ziegler-Natta procatalyst obtained via aprocess comprising: i) contacting a compound R⁴ _(z)MgX⁴ _(2-z) with analkoxy- or aryloxy-containing silane compound to give a firstintermediate reaction product, being a solid Mg(OR¹)_(x)X¹ _(2-x),wherein: R⁴ is the same as R¹ being a linear, branched or cyclichydrocarbyl group independently selected from alkyl, alkenyl, aryl,aralkyl or alkylaryl groups, and one or more combinations thereof;wherein said hydrocarbyl group is substituted or unsubstituted,optionally comprises one or more heteroatoms and has between 1 and 20carbon atoms; X⁴ and X¹ are each independently selected from the groupof consisting of fluoride (F⁻), chloride (Cl⁻), bromide (Br⁻) or iodide(I⁻); z is in a range of larger than 0 and smaller than 2, being 0<z<2;ii) optionally contacting the solid Mg(OR¹)_(x)X¹ _(2-x) obtained instep i) with at least one activating compound selected from the group ofactivating electron donors and metal alkoxide compounds of formulaM¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w) to obtain a secondintermediate product; wherein M¹ is a metal selected from the groupconsisting of Ti, Zr, Hf, Al or Si; M² is a metal being Si; v is thevalency of M¹ or M²; R² and R³ are each a linear, branched or cyclichydrocarbyl group independently selected from alkyl, alkenyl, aryl,aralkyl or alkylaryl groups, and one or more combinations thereof;wherein said hydrocarbyl group is substituted or unsubstituted,optionally comprises one or more heteroatoms, and has between 1 and 20carbon atoms; iii) contacting the first or second intermediate reactionproduct, obtained respectively in step i) or ii), with ahalogen-containing Ti-compound and optionally an internal electron donorto obtain said procatalyst; and B) contacting said procatalyst with aco-catalyst and at least one external electron donor being a compoundhaving the structure according to Formula I′.
 7. The process accordingto claim 6, wherein Mg(OR¹)_(x)X¹ _(2-x) is contacted in step ii) withtitanium tetraalkoxide and an alcohol as activating compounds.
 8. Theprocess according to claim 5, wherein the co-catalyst is a hydrocarbylaluminum compound represented by the formula R²¹ _(m)AIX²¹ _(3-m)wherein m=1 or 2, R is an alkyl, and X is a halide or alkoxide.
 9. Aprocess for preparing a polyolefin, comprising contacting at least oneolefin with the catalyst system according to claim
 1. 10. The processaccording to claim 9, wherein the at least one olefin is propylene or amixture of propylene and ethylene.
 11. A polyolefin obtained by theprocess according to claim 9, wherein the polyolefin has a lump contentbelow 10 wt. %.
 12. A shaped article comprising the polyolefin accordingto claim
 11. 13. (canceled)
 14. The catalyst composition according toclaim 4, wherein in L at least one of X and Y is selected from b), c) ord).
 15. The catalyst system according to claim 1, wherein theco-catalyst is a hydrocarbyl aluminum compound represented by theformula R²¹ _(m)AIX²¹ _(3-m) wherein m=1 or 2, R is an alkyl, and X is ahalide or alkoxide.
 16. A process for preparing a polyolefin, comprisingcontacting at least one olefin with the catalyst system according toclaim
 6. 17. The process according to claim 16, wherein the at least oneolefin is propylene or a mixture of propylene and ethylene.
 18. Theprocess according to claim 17, wherein the co-catalyst is a hydrocarbylaluminum compound represented by the formula R²¹ _(m)AIX²¹ _(3-m)wherein m=1 or 2, R is an alkyl, and X is a halide or alkoxide.
 19. Thepolyolefin of claim 11, wherein the polyolefin has a lump content belowbelow 4 wt. %.